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 | 0 |
| 2 | 2 |
| 3 | 5 |
| 4 | 22 |
| 5 | 92 |
| 6 | 415 |
| 7 | 1927 |
| 8 | 9198 |
| 9 | 44804 |
| 10 | 221880 |
| 11 | 1113730 |
| 12 | 5653747 |
| 13 | 28975962 |
| 14 | 149725355 |
| 15 | 779178092 |
| 16 | 4080167790 |
| 17 | 21483383992 |
| 18 | 113670233848 |
| 19 | 604070682354 |
| 20 | 3222823434608 |
| 21 | 17255628041720 |
| 22 | 92689459311470 |
| 23 | 499359484166994 |
| 24 | 2697571066055611 |
| 25 | 14608820993453132 |