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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 36 |
| 7 | 176 |
| 8 | 1030 |
| 9 | 7039 |
| 10 | 55098 |
| 11 | 486346 |
| 12 | 4780445 |
| 13 | 51787405 |
| 14 | 613045468 |
| 15 | 7873065045 |
| 16 | 109021348618 |
| 17 | 1619197654575 |
| 18 | 25675094145535 |
| 19 | 432908683794379 |
| 20 | 7733991639921585 |
| 21 | 145933532935469016 |
| 22 | 2900112108790279902 |
| 23 | 60543749629794205640 |
| 24 | 1324677739541613767983 |