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 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 24 |
| 6 | 120 |
| 7 | 140 |
| 8 | 858 |
| 9 | 924 |
| 10 | 1008 |
| 11 | 1120 |
| 12 | 10080 |
| 13 | 11088 |
| 14 | 12012 |
| 15 | 12870 |
| 16 | 176358 |
| 17 | 184756 |
| 18 | 194480 |
| 19 | 205920 |
| 20 | 3500640 |
| 21 | 3695120 |
| 22 | 3879876 |
| 23 | 4056234 |
| 24 | 87253605 |
| 25 | 90262350 |
| 26 | 93605400 |
| 27 | 97349616 |
| 28 | 2433740400 |
| 29 | 2527345800 |
| 30 | 2617608150 |
| 31 | 2704861755 |
| 32 | 57176602275 |
| 33 | 79526843550 |
| 34 | 81676217700 |
| 35 | 84009823920 |
| 36 | 86555576160 |
| 37 | 2630123704650 |
| 38 | 2687300306925 |
| 39 | 2856334013280 |