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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 49 |
| 6 | 168 |
| 7 | 594 |
| 8 | 2149 |
| 9 | 7920 |
| 10 | 29640 |
| 11 | 112359 |
| 12 | 430564 |
| 13 | 1665197 |
| 14 | 6491280 |
| 15 | 25478886 |
| 16 | 100611695 |
| 17 | 399421439 |
| 18 | 1593221090 |
| 19 | 6382176160 |
| 20 | 25664184349 |
| 21 | 103560846454 |
| 22 | 419215870860 |
| 23 | 1701907025715 |
| 24 | 6927658961599 |
| 25 | 28268225980197 |
| 26 | 115608889788304 |