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 | 2 |
| 3 | 6 |
| 4 | 25 |
| 5 | 129 |
| 6 | 784 |
| 7 | 5472 |
| 8 | 42993 |
| 9 | 374190 |
| 10 | 3564176 |
| 11 | 36808647 |
| 12 | 409067204 |
| 13 | 4861490200 |
| 14 | 61457674398 |
| 15 | 822732344816 |
| 16 | 11618029697489 |
| 17 | 172476856415121 |
| 18 | 2683881876383377 |
| 19 | 43660291710726058 |
| 20 | 740764460615030663 |
| 21 | 13080604188895285878 |
| 22 | 239939914279952537597 |
| 23 | 4564083798329838120034 |
| 24 | 89886989241387131773525 |
| 25 | 1830230258908641519168564 |