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 | 0 |
| 4 | 2 |
| 5 | 12 |
| 6 | 0 |
| 7 | 5 |
| 8 | 44 |
| 9 | 342 |
| 10 | 0 |
| 11 | 15 |
| 12 | 188 |
| 13 | 1854 |
| 14 | 18144 |
| 15 | 0 |
| 16 | 52 |
| 17 | 908 |
| 18 | 11196 |
| 19 | 130272 |
| 20 | 1545600 |
| 21 | 0 |
| 22 | 203 |
| 23 | 4860 |
| 24 | 74106 |
| 25 | 1016544 |
| 26 | 13818600 |
| 27 | 193030560 |
| 28 | 0 |
| 29 | 877 |
| 30 | 28428 |
| 31 | 531378 |
| 32 | 8535264 |
| 33 | 132204600 |
| 34 | 2065854240 |
| 35 | 33232948560 |