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 | 0 |
| 3 | 2 |
| 4 | 4 |
| 5 | 6 |
| 6 | 56 |
| 7 | 40 |
| 8 | 40 |
| 9 | 92 |
| 10 | 624 |
| 11 | 504 |
| 12 | 10880 |
| 13 | 6688 |
| 14 | 7400 |
| 15 | 19312 |
| 16 | 113792 |
| 17 | 122400 |
| 18 | 3979008 |
| 19 | 2239104 |
| 20 | 2915840 |
| 21 | 5777920 |
| 22 | 56689920 |
| 23 | 55372800 |
| 24 | 110218240 |
| 25 | 78453760 |
| 26 | 65815552 |
| 27 | 125480960 |
| 28 | 2057036800 |
| 29 | 1776107520 |
| 30 | 137449159680 |
| 31 | 56911196160 |
| 32 | 54069370880 |
| 33 | 127085826560 |
| 34 | 63757824000 |
| 35 | 96876953600 |
| 36 | 4341200912384 |
| 37 | 2258481971200 |
| 38 | 2411472967680 |
| 39 | 5056905641984 |
| 40 | 122267833425920 |