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 | 6 |
| 4 | 12 |
| 5 | 30 |
| 6 | 82 |
| 7 | 198 |
| 8 | 533 |
| 9 | 1459 |
| 10 | 4039 |
| 11 | 11634 |
| 12 | 34095 |
| 13 | 102520 |
| 14 | 316456 |
| 15 | 995709 |
| 16 | 3215552 |
| 17 | 10591412 |
| 18 | 35633438 |
| 19 | 122499429 |
| 20 | 428988392 |
| 21 | 1532929060 |
| 22 | 5579867442 |
| 23 | 20677066725 |
| 24 | 78027003260 |
| 25 | 299413756170 |
| 26 | 1168536196157 |
| 27 | 4635420192861 |
| 28 | 18678567555721 |
| 29 | 76451691937279 |
| 30 | 317625507668759 |