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 | 8 |
| 3 | 52 |
| 4 | 380 |
| 5 | 2734 |
| 6 | 20116 |
| 7 | 149942 |
| 8 | 1128388 |
| 9 | 8545180 |
| 10 | 65055556 |
| 11 | 497505902 |
| 12 | 3818857188 |
| 13 | 29405977172 |
| 14 | 227044808964 |
| 15 | 1757143904470 |
| 16 | 13626887453432 |
| 17 | 105870556547144 |
| 18 | 823864569255344 |
| 19 | 6420445347122416 |
| 20 | 50100342760566184 |