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 | 0 |
| 2 | 2 |
| 3 | 15 |
| 4 | 232 |
| 5 | 4535 |
| 6 | 114276 |
| 7 | 3478083 |
| 8 | 124625040 |
| 9 | 5135162607 |
| 10 | 239298611020 |
| 11 | 12443586907763 |
| 12 | 714352426078776 |
| 13 | 44874695909075799 |
| 14 | 3061971330141166548 |
| 15 | 225519631138748009955 |
| 16 | 17832309102333780001312 |