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 | 4 |
| 3 | 22 |
| 4 | 163 |
| 5 | 1567 |
| 6 | 18794 |
| 7 | 271784 |
| 8 | 4610375 |
| 9 | 89779703 |
| 10 | 1973367872 |
| 11 | 48308239934 |
| 12 | 1303031971629 |
| 13 | 38388256758585 |
| 14 | 1226260047168738 |
| 15 | 42211658188907700 |
| 16 | 1557608679494424852 |
| 17 | 61330673937954704316 |
| 18 | 2566587073634355132976 |
| 19 | 113752830534050498513512 |
| 20 | 5322732785525637634435108 |