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 | 9 |
| 3 | 271 |
| 4 | 16335 |
| 5 | 1525940 |
| 6 | 196284041 |
| 7 | 32409332818 |
| 8 | 6561153029810 |
| 9 | 1577073620254149 |
| 10 | 439541281384464800 |
| 11 | 139493983910450106067 |
| 12 | 49695878602452933374813 |
| 13 | 19646816226938989587513067 |
| 14 | 8537966749269377751401117583 |
| 15 | 4046350906270352192325991177139 |