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 | 0 |
| 4 | 0 |
| 5 | 32 |
| 6 | 12944 |
| 7 | 867328 |
| 8 | 22522960 |
| 9 | 328097824 |
| 10 | 3209594096 |
| 11 | 23460698496 |
| 12 | 137045115696 |
| 13 | 670158151296 |
| 14 | 2835083100640 |
| 15 | 10634260782464 |
| 16 | 36033282628832 |
| 17 | 111923478184128 |
| 18 | 322412415716896 |
| 19 | 869530617762304 |
| 20 | 2212626780591008 |
| 21 | 5346773160475488 |
| 22 | 12336574243905648 |
| 23 | 27303885052866048 |