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 | 6 |
| 2 | 90 |
| 3 | 1860 |
| 4 | 44730 |
| 5 | 1172556 |
| 6 | 32496156 |
| 7 | 936369720 |
| 8 | 27770358330 |
| 9 | 842090474940 |
| 10 | 25989269017140 |
| 11 | 813689707488840 |
| 12 | 25780447171287900 |
| 13 | 825043888527957000 |
| 14 | 26630804377937061000 |
| 15 | 865978374333905289360 |
| 16 | 28342398385058078078010 |
| 17 | 932905175625150142902300 |