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 | 0 |
| 1 | 3 |
| 2 | 25 |
| 3 | 154 |
| 4 | 837 |
| 5 | 4246 |
| 6 | 20618 |
| 7 | 97140 |
| 8 | 447661 |
| 9 | 2028478 |
| 10 | 9070110 |
| 11 | 40122028 |
| 12 | 175913250 |
| 13 | 765561564 |
| 14 | 3310623412 |
| 15 | 14238676712 |
| 16 | 60949133949 |
| 17 | 259809601870 |
| 18 | 1103420316566 |
| 19 | 4670886541308 |
| 20 | 19714134528598 |
| 21 | 82985455688276 |
| 22 | 348481959315660 |
| 23 | 1460179866076504 |
| 24 | 6106070639175122 |