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 | 13 |
| 2 | 109 |
| 3 | 749 |
| 4 | 4589 |
| 5 | 26093 |
| 6 | 140781 |
| 7 | 730605 |
| 8 | 3679725 |
| 9 | 18097645 |
| 10 | 87303661 |
| 11 | 414459373 |
| 12 | 1941186029 |
| 13 | 8987616749 |
| 14 | 41199871469 |
| 15 | 187228759533 |
| 16 | 844358755821 |
| 17 | 3782116386285 |
| 18 | 16838816966125 |
| 19 | 74563177424365 |
| 20 | 328550363440621 |
| 21 | 1441256130749933 |
| 22 | 6296699479008749 |