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 | 1 |
| 2 | 7 |
| 3 | 70 |
| 4 | 819 |
| 5 | 10472 |
| 6 | 141778 |
| 7 | 1997688 |
| 8 | 28989675 |
| 9 | 430321633 |
| 10 | 6503352856 |
| 11 | 99726673130 |
| 12 | 1547847846090 |
| 13 | 24269405074740 |
| 14 | 383846168712104 |
| 15 | 6116574500860880 |
| 16 | 98106248306858715 |
| 17 | 1582638261961640247 |
| 18 | 25661404527790252375 |
| 19 | 417980115131315136400 |