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 | 5 |
| 2 | 15 |
| 3 | 40 |
| 4 | 165 |
| 5 | 624 |
| 6 | 2620 |
| 7 | 11160 |
| 8 | 48915 |
| 9 | 217000 |
| 10 | 976872 |
| 11 | 4438920 |
| 12 | 20346320 |
| 13 | 93900240 |
| 14 | 435970980 |
| 15 | 2034504992 |
| 16 | 9536767665 |
| 17 | 44878791360 |
| 18 | 211927733500 |
| 19 | 1003867701480 |
| 20 | 4768372070592 |
| 21 | 22706531339280 |
| 22 | 108372083629260 |
| 23 | 518301258916440 |
| 24 | 2483526875798820 |