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 | 2 |
| 3 | 6 |
| 4 | 25 |
| 5 | 136 |
| 6 | 923 |
| 7 | 7557 |
| 8 | 72767 |
| 9 | 807896 |
| 10 | 10180274 |
| 11 | 143741731 |
| 12 | 2250285510 |
| 13 | 38715864581 |
| 14 | 726596076239 |
| 15 | 14780041925011 |
| 16 | 324070919795226 |
| 17 | 7622475922806634 |
| 18 | 191515981769983447 |
| 19 | 5120787153821434468 |
| 20 | 145222986971201544125 |
| 21 | 4355043425181710241819 |
| 22 | 137728970544635824065325 |