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 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 6 |
| 5 | 10 |
| 6 | 195 |
| 7 | 1281 |
| 8 | 5908 |
| 9 | 68076 |
| 10 | 758565 |
| 11 | 6486535 |
| 12 | 75598446 |
| 13 | 1059484218 |
| 14 | 13378016743 |
| 15 | 185273328345 |
| 16 | 2999003869800 |
| 17 | 48665352612376 |
| 18 | 816394913567433 |
| 19 | 15110162148144267 |
| 20 | 292156921946387170 |
| 21 | 5805684093139498470 |
| 22 | 122617308231635240331 |