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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 26 |
| 6 | 348 |
| 7 | 4466 |
| 8 | 61726 |
| 9 | 949795 |
| 10 | 16331482 |
| 11 | 312298796 |
| 12 | 6587217199 |
| 13 | 152030203190 |
| 14 | 3811719561156 |
| 15 | 103171205826822 |
| 16 | 2998417379370294 |
| 17 | 93127344062857976 |
| 18 | 3078376281077418971 |
| 19 | 107905190923235526392 |