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 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 36 |
| 4 | 160 |
| 5 | 692 |
| 6 | 2928 |
| 7 | 12200 |
| 8 | 50304 |
| 9 | 205940 |
| 10 | 838928 |
| 11 | 3405496 |
| 12 | 13788736 |
| 13 | 55723592 |
| 14 | 224863712 |
| 15 | 906365136 |
| 16 | 3649978880 |
| 17 | 14687731572 |
| 18 | 59067989072 |
| 19 | 237424661016 |
| 20 | 953914608320 |
| 21 | 3831159414552 |
| 22 | 15381896102432 |
| 23 | 61739966366256 |
| 24 | 247750559632640 |
| 25 | 993955865320392 |
| 26 | 3986890331450528 |