C# Number Pattern Programs

Beginner

6 min read

Updated: Nov 2026

3 examples

int + Console.Write

C# number pattern programs printed with int and Console.Write

Definition

Definition and Usage

A C# number pattern is a console program that prints integers in rows. The outer for loop chooses the row. The inner for loop prints each int with Console.Write, then Console.WriteLine ends that row.

Console.Write(n) prints the decimal digits of n and stays on the line. Single digits sit next to each other (123). Once a value reaches 10, add a space or call PadLeft so 10 and 11 do not become 1011.

The loop variable is the number.

Print col for 1, 2, 3… Print row to repeat the same digit. A separate int value that you increment is how running sequences cross from one row to the next.

Syntax

C# Syntax

Count the outer loop down when the first row should be the longest. The inner loop still walks 1 through the current width.

for (int row = rows; row >= 1; row--)
{
    for (int n = 1; n <= row; n++)
        Console.Write(n);    // digits, no space
    Console.WriteLine();    // end the row
}

Reference

How C# Prints a Number

Map each part of the console shape to a C# type or call.

Piece	C#	What it does
Digit	`Console.Write(n)`	Prints the `int` with no extra space
Same digit	`Console.Write(row)`	Repeats the row number on that line
Next value	`value++`	Keeps counting across columns and rows
New row	`Console.WriteLine()`	Finish the row
Width	`n.ToString().PadLeft(2)`	Two-digit columns stay aligned
Odd or even	`n % 2`	0/1 patterns from the remainder
One call	`string.Join("", Enumerable.Range(1, row))`	Same 1…row string without an inner loop

Code

C# Examples

Three console programs. Each one changes only the C# that chooses the int or its width.

Example 1 — Shrink the row with the outer loop

Start row at 5 and stop at 1. The inner loop prints 1 through row.

using System;

class DescendTriangle
{
    static void Main()
    {
        int rows = 5;

        for (int row = rows; row >= 1; row--)
        {
            for (int n = 1; n <= row; n++)
                Console.Write(n);
            Console.WriteLine();
        }
    }
}

How It Works

row-- makes each later line one digit shorter.
The inner for always restarts at 1, so every row begins with 1.
Console.Write(n) prints the int; WriteLine ends the row.

Example 2 — Print the row number, not the column

The inner loop only decides how many times to print. The value is row.

using System;

class RepeatRow
{
    static void Main()
    {
        int rows = 5;

        for (int row = 1; row <= rows; row++)
        {
            for (int col = 1; col <= row; col++)
                Console.Write(row);
            Console.WriteLine();
        }
    }
}

How It Works

Row 1 runs the inner loop once and prints 1.
Row 3 runs it three times and prints 3 each time.
Swap Console.Write(row) for Console.Write(col) and the line becomes 123.

Example 3 — Keep two-digit values aligned

PadLeft(2) gives every number the same width before the space.

using System;

class PaddedCounter
{
    static void Main()
    {
        int value = 1;

        for (int row = 1; row <= 4; row++)
        {
            for (int col = 1; col <= row; col++)
            {
                Console.Write(value.ToString().PadLeft(2));
                Console.Write(' ');
                value++;
            }
            Console.WriteLine();
        }
    }
}

How It Works

value lives outside both loops, so counting continues on the next row.
ToString().PadLeft(2) turns 1 into " 1" and leaves "10" as two characters.
The extra Console.Write(' ') separates columns.

Programs

62 C# Number Pattern Programs

Each card is a full console program: nested for loops, an int for the cell, and Console.Write. Open one for the walkthrough.

Number Pattern 1

Sample output

Number Pattern 2

Sample output

Number Pattern 3

Sample output

Number Pattern 4

Sample output

Number Pattern 5

Sample output

Number Pattern 6

Sample output

Number Pattern 7

Sample output

Number Pattern 8

Sample output

Number Pattern 9

Sample output

Number Pattern 10

Sample output

Number Pattern 11

Sample output

Number Pattern 12

Sample output

Number Pattern 13

Sample output

Number Pattern 14

Sample output

Number Pattern 15

Sample output

Number Pattern 16

Sample output

Number Pattern 17

Sample output

Number Pattern 18

Sample output

Number Pattern 19

Sample output

Number Pattern 20

Sample output

Number Pattern 21

Sample output

1
2 6
3 7 10
4 8 11 13 
5 9 12 14 15

Number Pattern 22

Sample output

Number Pattern 23

Sample output

1234554321
1234**4321
123****321
12******21
1********1

Number Pattern 24

Sample output

    1 
  2 3 4
5 6 7 8 9

Number Pattern 25

Sample output

Number Pattern 26

Sample output

Number Pattern 27

Sample output

Number Pattern 28

Sample output

0
909
89098
7890987
678909876
56789098765
4567890987654
345678909876543
23456789098765432
1234567890987654321

Number Pattern 29

Sample output

Number Pattern 30

Sample output

Number Pattern 31

Sample output

1
2*2
3*3*3
4*4*4*4
5*5*5*5*5
4*4*4*4
3*3*3
2*2
1

Number Pattern 32

Sample output

11
12 13
13 14 15
14 15 16 17
15 16 17 18 19

Number Pattern 33

Sample output

Number Pattern 34

Sample output

0
1 2 
2 3 4
3 4 5 6
4 5 6 7 8
5 6 7 8 9 10

Number Pattern 35

Sample output

             1
          2  3
       4  5  6
    7  8  9 10
11 12 13 14 15

Number Pattern 36

Sample output

Number Pattern 37

Sample output

Number Pattern 38

Sample output

 1  2  3  4  5
 6  7  8  9 
10 11 12
13 14 
15

Number Pattern 39

Sample output

Number Pattern 40

Sample output

Number Pattern 41

Sample output

                  1
              4   9  16
         25  36  49  64  81
    100 121 144 169 196 225 256
289 324 361 400 441 484 529 576 625

Number Pattern 42

Sample output

Number Pattern 43

Sample output

Number Pattern 44

Sample output

Number Pattern 45

Sample output

*000*000*
0*00*00*0
00*0*0*00
000***000

Number Pattern 46

Sample output

5 5 5 5 5 5 5 5 5
5 4 4 4 4 4 4 4 5
5 4 3 3 3 3 3 4 5
5 4 3 2 2 2 3 4 5
5 4 3 2 1 2 3 4 5

Number Pattern 47

Sample output

5 5 5 5 5 5 5 5 5
5 4 4 4 4 4 4 4 5
5 4 3 3 3 3 3 4 5
5 4 3 2 2 2 3 4 5
5 4 3 2 1 2 3 4 5
5 4 3 2 2 2 3 4 5
5 4 3 3 3 3 3 4 5
5 4 4 4 4 4 4 4 5
5 5 5 5 5 5 5 5 5

Number Pattern 48

Sample output

Number Pattern 49

Sample output

1
2 4
3 6 9
4 8 12 16
5 10 15 20 25
6 12 18 24 30 36
7 14 21 28 35 42 49
8 16 24 32 40 48 56 64
9 18 27 36 45 54 63 72 81
10 20 30 40 50 60 70 80 90 100

Number Pattern 50

Sample output

Number Pattern 51

Sample output

1
3 2
4 5 6
10 9 8 7
11 12 13 14 15

Number Pattern 52

Sample output

Number Pattern 53

Sample output

Number Pattern 54

Sample output

Number Pattern 55

Sample output

1
2 6
3 7 10
4 8 11 13
5 9 12 14 15

Number Pattern 56

Sample output

        1
      1 2 1
    1 2 3 2 1
  1 2 3 4 3 2 1
1 2 3 4 5 4 3 2 1

Number Pattern 57

Sample output

Number Pattern 58

Sample output

Number Pattern 59

Sample output

1  2  3  4  5
16          6
15          7
14          8
13 12 11 10 9

Number Pattern 60

Sample output

Number Pattern 61

Sample output

Number Pattern 62

Sample output

1    2    3    4    5    6    7    8    9   10
36  37   38   39   40   41   42   43   44   11
35  64   65   66   67   68   69   70   45   12
34  63   84   85   86   87   88   71   46   13
33  62   83   96   97   98   89   72   47   14
32  61   82   95  100   99   90   73   48   15
31  60   81   94   93   92   91   74   49   16
30  59   80   79   78   77   76   75   50   17
29  58   57   56   55   54   53   52   51   18
28  27   26   25   24   23   22   21   20   19

Frequently Asked Questions

Why do 10 and 11 run together in a C# pattern?

Console.Write(10) prints the characters 1 and 0 with no space after them. The next Write starts immediately, so 10 and 11 become 1011. Print a space, or use PadLeft, when values can be more than one digit.

What is the difference between Console.Write and Console.WriteLine?

Console.Write prints and stays on the same line, which is how each number in a row is placed. Console.WriteLine ends the row. Call WriteLine once after the inner loop.

How do I line up two-digit numbers in C#?

Give every value the same width. value.ToString().PadLeft(2) pads on the left with spaces. Composite format Console.Write("{0,3}", value) does the same with a width of 3.

Can I skip the inner loop with LINQ?

Yes. Console.WriteLine(string.Join("", Enumerable.Range(1, row))) prints 1 through row as one string. Nested for loops are what these programs teach; Enumerable.Range is a shortcut once the shape is clear.

Next: Number Pattern 1

A full C# walkthrough of the descending number triangle, from the outer for through Console.WriteLine.

Number Pattern 1 →

About the author

Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

Experience 12 years building web and cloud systems
Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

28 people found this page helpful

C# Star Pattern Programs C# Number Pattern 1

C# Number Pattern Programs

Definition and Usage

C# Syntax

How C# Prints a Number

C# Examples

Example 1 — Shrink the row with the outer loop

How It Works

Example 2 — Print the row number, not the column

How It Works

Example 3 — Keep two-digit values aligned

How It Works

62 C# Number Pattern Programs

Frequently Asked Questions

Related C# Topics

Number Pattern 1

Star Patterns

Alphabet Patterns

C# Strings

Next: Number Pattern 1

About the author