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 | 4 |
| 2 | 9 |
| 3 | 35 |
| 4 | 105 |
| 5 | 616 |
| 6 | 1313 |
| 7 | 5049 |
| 8 | 9310 |
| 9 | 28865 |
| 10 | 132385 |
| 11 | 212102 |
| 12 | 800569 |
| 13 | 1827903 |
| 14 | 2720223 |
| 15 | 5863438 |
| 16 | 17486343 |
| 17 | 49077380 |
| 18 | 68411805 |
| 19 | 179539163 |
| 20 | 333501555 |
| 21 | 451555297 |
| 22 | 1094043350 |
| 23 | 1937092927 |
| 24 | 4449637325 |
| 25 | 12923400210 |
| 26 | 21662593726 |
| 27 | 27938641850 |
| 28 | 46132984623 |
| 29 | 59072140160 |