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 | 3 |
| 3 | 12 |
| 4 | 55 |
| 5 | 276 |
| 6 | 1477 |
| 7 | 8296 |
| 8 | 48393 |
| 9 | 291010 |
| 10 | 1794320 |
| 11 | 11297760 |
| 12 | 72413640 |
| 13 | 471309944 |
| 14 | 3108745785 |
| 15 | 20746732688 |
| 16 | 139899430981 |
| 17 | 952127880138 |
| 18 | 6533934575018 |
| 19 | 45175430719240 |
| 20 | 314467004704818 |
| 21 | 2202576030828096 |
| 22 | 15514620388706488 |
| 23 | 109851319423632192 |
| 24 | 781531332298053400 |