This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 21 |
| 3 | 105 |
| 4 | 210 |
| 5 | 231 |
| 6 | 378 |
| 7 | 630 |
| 8 | 861 |
| 9 | 903 |
| 10 | 1176 |
| 11 | 1596 |
| 12 | 1953 |
| 13 | 2016 |
| 14 | 2415 |
| 15 | 3003 |
| 16 | 3486 |
| 17 | 3570 |
| 18 | 4095 |
| 19 | 4851 |
| 20 | 5460 |
| 21 | 5565 |
| 22 | 6216 |
| 23 | 7140 |
| 24 | 7875 |
| 25 | 8001 |
| 26 | 8778 |
| 27 | 9870 |
| 28 | 10731 |
| 29 | 10878 |
| 30 | 11781 |
| 31 | 13041 |
| 32 | 14028 |
| 33 | 14196 |
| 34 | 15225 |
| 35 | 16653 |
| 36 | 17766 |
| 37 | 17955 |
| 38 | 19110 |
| 39 | 20706 |
| 40 | 21945 |
| 41 | 22155 |
| 42 | 23436 |
| 43 | 25200 |