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 | 15 |
| 3 | 99 |
| 4 | 519 |
| 5 | 3165 |
| 6 | 19503 |
| 7 | 115053 |
| 8 | 688803 |
| 9 | 4141863 |
| 10 | 24778355 |
| 11 | 148376447 |
| 12 | 889216143 |
| 13 | 5326274463 |
| 14 | 31903872267 |
| 15 | 191123789739 |
| 16 | 1144894457103 |
| 17 | 6858232252437 |
| 18 | 41083285178247 |
| 19 | 246102886383661 |
| 20 | 1474237118571467 |
| 21 | 8831178384769525 |
| 22 | 52901735792001759 |