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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 39 |
| 7 | 126 |
| 8 | 537 |
| 9 | 2358 |
| 10 | 11690 |
| 11 | 61689 |
| 12 | 351725 |
| 13 | 2126496 |
| 14 | 13639244 |
| 15 | 92197509 |
| 16 | 655035225 |
| 17 | 4874404107 |
| 18 | 37893368072 |
| 19 | 306986431846 |
| 20 | 2586209738004 |
| 21 | 22612848403442 |
| 22 | 204850732418594 |
| 23 | 1919652428481929 |
| 24 | 18581619724011091 |
| 25 | 185543613289200937 |
| 26 | 1908894098864372104 |