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 | 8 |
| 3 | 47 |
| 4 | 264 |
| 5 | 1480 |
| 6 | 8305 |
| 7 | 46616 |
| 8 | 261663 |
| 9 | 1468752 |
| 10 | 8244304 |
| 11 | 46276385 |
| 12 | 259755560 |
| 13 | 1458042831 |
| 14 | 8184190168 |
| 15 | 45938958232 |
| 16 | 257861540369 |
| 17 | 1447411446840 |
| 18 | 8124514782015 |
| 19 | 45603992276896 |
| 20 | 255981331487648 |