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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 1 |
| 5 | 12 |
| 6 | 6 |
| 7 | 1 |
| 8 | 86 |
| 9 | 84 |
| 10 | 24 |
| 11 | 1 |
| 12 | 840 |
| 13 | 1110 |
| 14 | 480 |
| 15 | 120 |
| 16 | 1 |
| 17 | 11642 |
| 18 | 16620 |
| 19 | 9120 |
| 20 | 3240 |
| 21 | 720 |
| 22 | 1 |
| 23 | 227892 |
| 24 | 300846 |
| 25 | 185640 |
| 26 | 82320 |
| 27 | 25200 |
| 28 | 5040 |
| 29 | 1 |
| 30 | 6285806 |
| 31 | 6810804 |
| 32 | 4299624 |
| 33 | 2142000 |
| 34 | 816480 |
| 35 | 221760 |
| 36 | 40320 |
| 37 | 1 |
| 38 | 243593040 |
| 39 | 199239270 |
| 40 | 117205200 |
| 41 | 60890760 |
| 42 | 26157600 |