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 | -4 |
| 4 | 6 |
| 5 | 0 |
| 6 | 0 |
| 7 | 32736 |
| 8 | 131076 |
| 9 | 0 |
| 10 | 0 |
| 11 | 3669012 |
| 12 | 9172952 |
| 13 | 0 |
| 14 | 0 |
| 15 | 95691552 |
| 16 | 188239518 |
| 17 | 0 |
| 18 | 0 |
| 19 | 1142929524 |
| 20 | 1959705000 |
| 21 | 0 |
| 22 | 0 |
| 23 | 8506686816 |
| 24 | 13293227112 |
| 25 | 0 |
| 26 | 0 |
| 27 | 45763087664 |
| 28 | 67073100864 |
| 29 | 0 |
| 30 | 0 |
| 31 | 195387947712 |
| 32 | 272567759508 |
| 33 | 0 |
| 34 | 0 |
| 35 | 698077783656 |
| 36 | 938807478318 |
| 37 | 0 |
| 38 | 0 |
| 39 | 2176654050912 |