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) |
|---|---|
| 1 | 5 |
| 2 | 130 |
| 3 | 1660 |
| 4 | 16820 |
| 5 | 152230 |
| 6 | 1275680 |
| 7 | 10154290 |
| 8 | 77897010 |
| 9 | 581452680 |
| 10 | 4250594690 |
| 11 | 30572999140 |
| 12 | 217099260110 |
| 13 | 1525905283670 |
| 14 | 10636695448300 |
| 15 | 73649615037480 |
| 16 | 507171127397480 |
| 17 | 3476871213780220 |
| 18 | 23747634842538120 |