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 | 0 |
| 1 | 1 |
| 2 | 11 |
| 3 | 84 |
| 4 | 642 |
| 5 | 5633 |
| 6 | 59021 |
| 7 | 736944 |
| 8 | 10839316 |
| 9 | 185361065 |
| 10 | 3637063343 |
| 11 | 80939054884 |
| 12 | 2023405966486 |
| 13 | 56362728831929 |
| 14 | 1736960568923505 |
| 15 | 58853395571312176 |
| 16 | 2180579093801111176 |
| 17 | 87921539854223957169 |
| 18 | 3841160785119756991059 |