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) |
|---|---|
| 3 | 1 |
| 4 | 10 |
| 5 | 68 |
| 6 | 402 |
| 7 | 2258 |
| 8 | 12072 |
| 9 | 64963 |
| 10 | 338824 |
| 11 | 1817063 |
| 12 | 9467940 |
| 13 | 51258781 |
| 14 | 269085042 |
| 15 | 1475551064 |
| 16 | 7822940886 |
| 17 | 43422818989 |
| 18 | 232480179882 |
| 19 | 1303561020575 |
| 20 | 7040175844640 |
| 21 | 39786449049369 |
| 22 | 216469879238194 |
| 23 | 1230485470688864 |
| 24 | 6736096483008440 |
| 25 | 38451562317699992 |
| 26 | 211571284685596944 |