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) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 13 |
| 6 | 73 |
| 7 | 301 |
| 8 | 2069 |
| 9 | 11581 |
| 10 | 95401 |
| 11 | 673261 |
| 12 | 6487445 |
| 13 | 55213453 |
| 14 | 610093513 |
| 15 | 6077248381 |
| 16 | 75796724309 |
| 17 | 864806272861 |
| 18 | 12020754177001 |
| 19 | 154546274524621 |
| 20 | 2369364111428885 |
| 21 | 33888536448984493 |
| 22 | 568128719132038153 |
| 23 | 8947078682269788061 |