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) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 2 |
| 4 | 120 |
| 5 | 80 |
| 6 | 15 |
| 7 | 4760 |
| 8 | 3552 |
| 9 | 860 |
| 10 | 64 |
| 11 | 249984 |
| 12 | 199168 |
| 13 | 57064 |
| 14 | 6576 |
| 15 | 220 |
| 16 | 17512704 |
| 17 | 14548480 |
| 18 | 4643712 |
| 19 | 681984 |
| 20 | 42112 |
| 21 | 672 |
| 22 | 1599330304 |
| 23 | 1367568384 |
| 24 | 469942528 |
| 25 | 80506880 |
| 26 | 6849792 |
| 27 | 242688 |
| 28 | 1904 |
| 29 | 185616337920 |
| 30 | 162107703296 |
| 31 | 58754129408 |