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 | 9 |
| 3 | 76 |
| 4 | 679 |
| 5 | 6576 |
| 6 | 69299 |
| 7 | 792926 |
| 8 | 9812079 |
| 9 | 130741156 |
| 10 | 1867777339 |
| 11 | 28494131106 |
| 12 | 462487232519 |
| 13 | 7959671021576 |
| 14 | 144813873037539 |
| 15 | 2777366346993766 |
| 16 | 56009230972732639 |
| 17 | 1184896664408025036 |
| 18 | 26240470547134420619 |
| 19 | 607133649024919944266 |
| 20 | 14649976322598313989879 |