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 | 2 |
| 3 | 14 |
| 4 | 122 |
| 5 | 1278 |
| 6 | 15802 |
| 7 | 225886 |
| 8 | 3670074 |
| 9 | 66843902 |
| 10 | 1349399162 |
| 11 | 29912161758 |
| 12 | 722399486074 |
| 13 | 18881553923326 |
| 14 | 531063524702778 |
| 15 | 15993786127174238 |
| 16 | 513533806880120762 |
| 17 | 17512128958240460286 |
| 18 | 632099987274779910394 |
| 19 | 24076353238897830158302 |