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 | 4 |
| 3 | 37 |
| 4 | 631 |
| 5 | 17266 |
| 6 | 692785 |
| 7 | 38325925 |
| 8 | 2795925136 |
| 9 | 260056965205 |
| 10 | 30038178784699 |
| 11 | 4218296308789630 |
| 12 | 707778995370264001 |
| 13 | 139840360858571766121 |