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) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 25 |
| 7 | 135 |
| 8 | 892 |
| 9 | 6937 |
| 10 | 61886 |
| 11 | 621956 |
| 12 | 6946471 |
| 13 | 85302935 |
| 14 | 1141820808 |
| 15 | 16540534553 |
| 16 | 257745010762 |
| 17 | 4298050731298 |
| 18 | 76356627952069 |
| 19 | 1439506369337319 |
| 20 | 28699241994332940 |
| 21 | 603229325513240569 |
| 22 | 13330768181611378558 |
| 23 | 308967866671489907656 |
| 24 | 7493481669479297191451 |
| 25 | 189793402599733802743015 |
| 26 | 5010686896406348299630712 |