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 | 0 |
| 3 | 28 |
| 4 | 326 |
| 5 | 0 |
| 6 | 0 |
| 7 | 29920 |
| 8 | 126852 |
| 9 | 0 |
| 10 | 0 |
| 11 | 3709812 |
| 12 | 9196504 |
| 13 | 0 |
| 14 | 0 |
| 15 | 95434272 |
| 16 | 188147358 |
| 17 | 0 |
| 18 | 0 |
| 19 | 1143698644 |
| 20 | 1960123560 |
| 21 | 0 |
| 22 | 0 |
| 23 | 8506234464 |
| 24 | 13291495272 |
| 25 | 0 |
| 26 | 0 |
| 27 | 45758964656 |
| 28 | 67076795456 |
| 29 | 0 |
| 30 | 0 |
| 31 | 195400412352 |
| 32 | 272568976020 |
| 33 | 0 |
| 34 | 0 |