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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 32 |
| 6 | 172 |
| 7 | 1052 |
| 8 | 7177 |
| 9 | 53792 |
| 10 | 437992 |
| 11 | 3841772 |
| 12 | 36060262 |
| 13 | 360234512 |
| 14 | 3812425912 |
| 15 | 42576007352 |
| 16 | 500022862357 |
| 17 | 6157034292032 |
| 18 | 79278216024592 |
| 19 | 1064888929532492 |
| 20 | 14890014669234922 |
| 21 | 216315676347260912 |