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 | 3 |
| 4 | 0 |
| 5 | 0 |
| 6 | 15 |
| 7 | 0 |
| 8 | 8 |
| 9 | 84 |
| 10 | 0 |
| 11 | 110 |
| 12 | 495 |
| 13 | 0 |
| 14 | 1092 |
| 15 | 3018 |
| 16 | 120 |
| 17 | 9520 |
| 18 | 18870 |
| 19 | 2907 |
| 20 | 77520 |
| 21 | 120270 |
| 22 | 43890 |
| 23 | 606188 |
| 24 | 780023 |
| 25 | 531300 |
| 26 | 4620200 |
| 27 | 5161377 |
| 28 | 5651100 |
| 29 | 34622172 |
| 30 | 35045340 |
| 31 | 55234560 |
| 32 | 256503672 |
| 33 | 245772464 |
| 34 | 508930224 |
| 35 | 1886151225 |
| 36 | 1788167610 |
| 37 | 4491607230 |