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 | 765 |
| 4 | 4881 |
| 5 | 29369 |
| 6 | 169919 |
| 7 | 956237 |
| 8 | 5272945 |
| 9 | 28632525 |
| 10 | 153638211 |
| 11 | 816715073 |
| 12 | 4309138419 |
| 13 | 22598433555 |
| 14 | 117926579385 |
| 15 | 612863125965 |
| 16 | 3174156512865 |
| 17 | 16392351740045 |
| 18 | 84448387609475 |
| 19 | 434142126555125 |
| 20 | 2227861180841895 |
| 21 | 11414655603043335 |
| 22 | 58403793025471605 |