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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 27 |
| 5 | 86 |
| 6 | 393 |
| 7 | 1688 |
| 8 | 8291 |
| 9 | 44143 |
| 10 | 248428 |
| 11 | 1480073 |
| 12 | 9440049 |
| 13 | 63265606 |
| 14 | 444309232 |
| 15 | 3273807272 |
| 16 | 25227429123 |
| 17 | 202458174614 |
| 18 | 1689474026499 |
| 19 | 14636685675142 |
| 20 | 131413462612012 |
| 21 | 1220636654904548 |
| 22 | 11712836883408675 |
| 23 | 115956109213769404 |
| 24 | 1182944504931376337 |