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 | 4 |
| 3 | 14 |
| 4 | 55 |
| 5 | 235 |
| 6 | 1112 |
| 7 | 5672 |
| 8 | 30783 |
| 9 | 175733 |
| 10 | 1042812 |
| 11 | 6385278 |
| 12 | 40093375 |
| 13 | 257031667 |
| 14 | 1676581863 |
| 15 | 11098295287 |
| 16 | 74401300872 |
| 17 | 504290610004 |
| 18 | 3451219615401 |
| 19 | 23821766422463 |
| 20 | 165684694539918 |
| 21 | 1160267446543182 |
| 22 | 8175446407807625 |
| 23 | 57928670942338011 |
| 24 | 412561582740147643 |