Triangular Numbers 1–100
The first 100 triangular numbers with formula n(n+1)/2.
| n | Triangular number |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 10 |
| 5 | 15 |
| 6 | 21 |
| 7 | 28 |
| 8 | 36 |
| 9 | 45 |
| 10 | 55 |
| 11 | 66 |
| 12 | 78 |
| 13 | 91 |
| 14 | 105 |
| 15 | 120 |
| 16 | 136 |
| 17 | 153 |
| 18 | 171 |
| 19 | 190 |
| 20 | 210 |
| 21 | 231 |
| 22 | 253 |
| 23 | 276 |
| 24 | 300 |
| 25 | 325 |
| 26 | 351 |
| 27 | 378 |
| 28 | 406 |
| 29 | 435 |
| 30 | 465 |
| 31 | 496 |
| 32 | 528 |
| 33 | 561 |
| 34 | 595 |
| 35 | 630 |
| 36 | 666 |
| 37 | 703 |
| 38 | 741 |
| 39 | 780 |
| 40 | 820 |
| 41 | 861 |
| 42 | 903 |
| 43 | 946 |
| 44 | 990 |
| 45 | 1,035 |
| 46 | 1,081 |
| 47 | 1,128 |
| 48 | 1,176 |
| 49 | 1,225 |
| 50 | 1,275 |
| 51 | 1,326 |
| 52 | 1,378 |
| 53 | 1,431 |
| 54 | 1,485 |
| 55 | 1,540 |
| 56 | 1,596 |
| 57 | 1,653 |
| 58 | 1,711 |
| 59 | 1,770 |
| 60 | 1,830 |
| 61 | 1,891 |
| 62 | 1,953 |
| 63 | 2,016 |
| 64 | 2,080 |
| 65 | 2,145 |
| 66 | 2,211 |
| 67 | 2,278 |
| 68 | 2,346 |
| 69 | 2,415 |
| 70 | 2,485 |
| 71 | 2,556 |
| 72 | 2,628 |
| 73 | 2,701 |
| 74 | 2,775 |
| 75 | 2,850 |
| 76 | 2,926 |
| 77 | 3,003 |
| 78 | 3,081 |
| 79 | 3,160 |
| 80 | 3,240 |
| 81 | 3,321 |
| 82 | 3,403 |
| 83 | 3,486 |
| 84 | 3,570 |
| 85 | 3,655 |
| 86 | 3,741 |
| 87 | 3,828 |
| 88 | 3,916 |
| 89 | 4,005 |
| 90 | 4,095 |
| 91 | 4,186 |
| 92 | 4,278 |
| 93 | 4,371 |
| 94 | 4,465 |
| 95 | 4,560 |
| 96 | 4,656 |
| 97 | 4,753 |
| 98 | 4,851 |
| 99 | 4,950 |
| 100 | 5,050 |
How to use this table
The first 100 triangular numbers with formula n(n+1)/2. Use it as a reference, for practice, or to check your own work. On large tables, scroll horizontally on a phone. Tap cells to visually track a row or value.