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 | 8 |
| 5 | 45 |
| 6 | 221 |
| 7 | 1016 |
| 8 | 4506 |
| 9 | 19572 |
| 10 | 83950 |
| 11 | 357310 |
| 12 | 1513513 |
| 13 | 6392134 |
| 14 | 26948764 |
| 15 | 113500985 |
| 16 | 477801129 |
| 17 | 2011058681 |
| 18 | 8464967333 |
| 19 | 35637556603 |
| 20 | 150075181365 |
| 21 | 632191803847 |
| 22 | 2664023530675 |
| 23 | 11229995113561 |
| 24 | 47355649431833 |
| 25 | 199760722776165 |