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 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 12 |
| 7 | 72 |
| 8 | 352 |
| 9 | 1472 |
| 10 | 5756 |
| 11 | 26336 |
| 12 | 180116 |
| 13 | 1577006 |
| 14 | 13720566 |
| 15 | 109776526 |
| 16 | 829240726 |
| 17 | 6488348726 |
| 18 | 59134377126 |
| 19 | 640605185526 |
| 20 | 7502207070150 |
| 21 | 87309498759810 |
| 22 | 989782736128170 |
| 23 | 11277397727184650 |
| 24 | 136523328121058170 |
| 25 | 1817775858886701082 |