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 | 11 |
| 2 | 90 |
| 3 | 648 |
| 4 | 4272 |
| 5 | 25810 |
| 6 | 145138 |
| 7 | 766518 |
| 8 | 3834490 |
| 9 | 18286018 |
| 10 | 83570177 |
| 11 | 367774928 |
| 12 | 1564548863 |
| 13 | 6452004367 |
| 14 | 25847879345 |
| 15 | 100777951798 |
| 16 | 383035877989 |
| 17 | 1421435174008 |
| 18 | 5157779243758 |
| 19 | 18324309623403 |
| 20 | 63818201253153 |