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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 7 |
| 6 | 37 |
| 7 | 104 |
| 8 | 766 |
| 9 | 3970 |
| 10 | 43318 |
| 11 | 431932 |
| 12 | 7695805 |
| 13 | 137066448 |
| 14 | 4015896016 |
| 15 | 128095791922 |
| 16 | 6371333036059 |
| 17 | 355704307903818 |
| 18 | 30153126159555641 |
| 19 | 2952926822418475378 |
| 20 | 431453249608567040694 |
| 21 | 73569487283165427567144 |
| 22 | 18558756256964594960321428 |