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) |
|---|---|
| 5 | 1 |
| 6 | 2 |
| 7 | 7 |
| 8 | 24 |
| 9 | 81 |
| 10 | 274 |
| 11 | 927 |
| 12 | 3132 |
| 13 | 10552 |
| 14 | 35395 |
| 15 | 118065 |
| 16 | 391320 |
| 17 | 1288260 |
| 18 | 4212091 |
| 19 | 13679558 |
| 20 | 44141377 |
| 21 | 141571286 |
| 22 | 451475589 |
| 23 | 1432198967 |
| 24 | 4521270066 |
| 25 | 14209424215 |
| 26 | 44474645476 |
| 27 | 138681426899 |
| 28 | 430955113144 |
| 29 | 1334997086607 |