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 | 3 |
| 3 | 12 |
| 4 | 1 |
| 5 | 56 |
| 6 | 15 |
| 7 | 288 |
| 8 | 165 |
| 9 | 8 |
| 10 | 1584 |
| 11 | 1611 |
| 12 | 252 |
| 13 | 9152 |
| 14 | 14805 |
| 15 | 4956 |
| 16 | 180 |
| 17 | 54912 |
| 18 | 131307 |
| 19 | 77992 |
| 20 | 9132 |
| 21 | 339456 |
| 22 | 1138261 |
| 23 | 1074564 |
| 24 | 268980 |
| 25 | 8064 |
| 26 | 2149888 |
| 27 | 9713835 |
| 28 | 13545216 |
| 29 | 6010220 |
| 30 | 579744 |
| 31 | 13891584 |
| 32 | 81968469 |
| 33 | 160174960 |
| 34 | 112868844 |
| 35 | 23235300 |
| 36 | 604800 |
| 37 | 91287552 |
| 38 | 685888171 |
| 39 | 1805010948 |
| 40 | 1877530740 |
| 41 | 684173164 |
| 42 | 57170880 |
| 43 | 608583680 |
| 44 | 5702382933 |
| 45 | 19588944336 |
| 46 | 28540603884 |
| 47 | 16497874380 |
| 48 | 2936606400 |
| 49 | 68428800 |
| 50 | 4107939840 |
| 51 | 47168678571 |
| 52 | 206254571236 |
| 53 | 404562365316 |
| 54 | 344901105444 |
| 55 | 108502598960 |
| 56 | 8099018496 |