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 | 1 |
| 3 | 3 |
| 4 | 7 |
| 5 | 25 |
| 6 | 91 |
| 7 | 329 |
| 8 | 1415 |
| 9 | 6297 |
| 10 | 29431 |
| 11 | 151085 |
| 12 | 802099 |
| 13 | 4506957 |
| 14 | 26836083 |
| 15 | 165586321 |
| 16 | 1074740079 |
| 17 | 7268876881 |
| 18 | 50985776815 |
| 19 | 372854157589 |
| 20 | 2820244541675 |
| 21 | 22087612114805 |
| 22 | 179014336044171 |
| 23 | 1495539626297689 |
| 24 | 12894921568568999 |
| 25 | 114481871464864825 |