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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 510 |
| 3 | 19680 |
| 4 | 262140 |
| 5 | 1953120 |
| 6 | 10077690 |
| 7 | 40353600 |
| 8 | 134217720 |
| 9 | 387420480 |
| 10 | 999999990 |
| 11 | 2357947680 |
| 12 | 5159780340 |
| 13 | 10604499360 |
| 14 | 20661046770 |
| 15 | 38443359360 |
| 16 | 68719476720 |
| 17 | 118587876480 |
| 18 | 198359290350 |
| 19 | 322687697760 |
| 20 | 511999999980 |
| 21 | 794280046560 |
| 22 | 1207269217770 |
| 23 | 1801152661440 |
| 24 | 2641807540200 |