C Number Pattern Programs

Beginner

📚 Updated: Aug 2025

Nested loops

Collection of C number pattern programs: numeric triangles, pyramids, and grid-style figures

Understanding number patterns

Number pattern programs print digits in rows and columns to form triangles, pyramids, diamonds, and other figures. They are one of the best ways to practice nested for loops and printf formatting in C.

From simple ascending and descending triangles to sequences mixed with stars or spaces, each exercise sharpens how you think about row indices, column bounds, and the value you print at each cell.

Why explore number patterns?

Digits make it easy to see when row logic drifts: one wrong inner bound and the sequence breaks in a way you can spot immediately.

Math and loops together

Many patterns echo arithmetic progressions, running sums, or tables. Writing them in C connects formulas on paper to what actually prints in the console.

Structured problem solving

You decide what each row starts with, how many values it prints, and how spaces align the block. That is the same decomposition skill you use in larger programs.

Interview-friendly drills

Entry-level C screenings often include a small triangle or pyramid. Working through these patterns prepares you to code under time pressure without freezing.

How to use this collection

Treat the list below as a menu: skim previews, open a tutorial when a shape matches what you need, then adapt the row counts and rules for your own exercises.

Start with familiar shapes

If you are new, begin with Number Pattern 1 and move forward. Each page shows output, complete C code, and a clear walkthrough.

Change one rule at a time

After a program works, adjust row count, starting value, or spacing. Re-run and compare output so you see exactly which loop controls which part of the figure.

Pair with stars and letters

The same loop skeletons appear in star patterns and alphabet patterns. Once digits feel natural, swapping the printed symbol is straightforward.

Complete list of C number pattern programs

Below are 62 number pattern programs in C. Each card shows sample output; open it for the full program, logic breakdown, variations, and FAQs.

Number Pattern 1

Number Pattern 2

Number Pattern 3

Number Pattern 4

Number Pattern 5

Number Pattern 6

Number Pattern 7

Number Pattern 8

Number Pattern 9

Number Pattern 10

Number Pattern 11

Number Pattern 12

Number Pattern 13

Number Pattern 14

Number Pattern 15

Number Pattern 16

Number Pattern 17

Number Pattern 18

Number Pattern 19

Number Pattern 20

Number Pattern 21

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

Number Pattern 22

Number Pattern 23

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

Number Pattern 24

    1 
  2 3 4
5 6 7 8 9

Number Pattern 25

Number Pattern 26

Number Pattern 27

Number Pattern 28

0
909
89098
7890987
678909876
56789098765
4567890987654
345678909876543
23456789098765432
1234567890987654321

Number Pattern 29

Number Pattern 30

Number Pattern 31

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

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

Number Pattern 33

Number Pattern 34

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

Number Pattern 35

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

Number Pattern 36

Number Pattern 37

Number Pattern 38

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

Number Pattern 39

Number Pattern 40

Number Pattern 41

                  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

Number Pattern 43

Number Pattern 44

Number Pattern 45

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

Number Pattern 46

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

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

Number Pattern 49

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

Number Pattern 51

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

Number Pattern 52

Number Pattern 53

Number Pattern 54

Number Pattern 55

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

Number Pattern 56

        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

Number Pattern 58

Number Pattern 59

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

Number Pattern 60

Number Pattern 61

Number Pattern 62

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

Did you know?

Combining printf("%d", n) with width specifiers like %2d or %3d is often the difference between a crooked triangle and columns that line up when values become two or three digits wide.

Ready to code?

Open Number Pattern 1 for a full walkthrough, runnable C source, and common interview questions.

Number Pattern 1 →

About the author

Mari Selvan M P

Mari Selvan M P 🔗

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