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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 16 |
| 5 | 66 |
| 6 | 300 |
| 7 | 1314 |
| 8 | 5884 |
| 9 | 26304 |
| 10 | 118633 |
| 11 | 537255 |
| 12 | 2447172 |
| 13 | 11197710 |
| 14 | 51473017 |
| 15 | 237569535 |
| 16 | 1100655430 |
| 17 | 5117008440 |
| 18 | 23865566651 |
| 19 | 111636805905 |
| 20 | 523632748312 |
| 21 | 2462303017950 |
| 22 | 11605730134178 |
| 23 | 54821137926588 |
| 24 | 259479816361256 |
| 25 | 1230496691745816 |
| 26 | 5845551200648015 |