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 | 1 |
| 3 | 7 |
| 4 | 13 |
| 5 | 151 |
| 6 | 421 |
| 7 | 6847 |
| 8 | 25453 |
| 9 | 532231 |
| 10 | 2473141 |
| 11 | 63206287 |
| 12 | 352444093 |
| 13 | 10645162711 |
| 14 | 69251478661 |
| 15 | 2413453999327 |
| 16 | 17943523153933 |
| 17 | 708721089607591 |
| 18 | 5927841361456981 |
| 19 | 261679010699505967 |
| 20 | 2431910546406522973 |
| 21 | 118654880542567722871 |
| 22 | 1212989379862721528101 |