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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 45 |
| 6 | 210 |
| 7 | 1176 |
| 8 | 6670 |
| 9 | 41041 |
| 10 | 258840 |
| 11 | 1697403 |
| 12 | 11359761 |
| 13 | 77956341 |
| 14 | 543625851 |
| 15 | 3855429766 |
| 16 | 27702225271 |
| 17 | 201515674128 |
| 18 | 1481195012220 |
| 19 | 10991843660826 |
| 20 | 82256068767106 |
| 21 | 620288742329028 |
| 22 | 4709854127998971 |
| 23 | 35987845277616940 |
| 24 | 276563426284762620 |