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 | 3 |
| 4 | 7 |
| 5 | 19 |
| 6 | 41 |
| 7 | 113 |
| 8 | 261 |
| 9 | 713 |
| 10 | 1681 |
| 11 | 4567 |
| 12 | 10993 |
| 13 | 29717 |
| 14 | 72493 |
| 15 | 195269 |
| 16 | 481261 |
| 17 | 1292729 |
| 18 | 3211263 |
| 19 | 8606801 |
| 20 | 21515135 |
| 21 | 57561815 |
| 22 | 144631085 |
| 23 | 386382359 |
| 24 | 974968645 |
| 25 | 2601469419 |
| 26 | 6587913395 |
| 27 | 17560287513 |
| 28 | 44605607915 |
| 29 | 118794020215 |
| 30 | 302552020141 |
| 31 | 805154546027 |