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 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 362880 |
| 10 | 362870 |
| 11 | 362770 |
| 12 | 361560 |
| 13 | 345720 |
| 14 | 122640 |
| 15 | -3240720 |
| 16 | -57294720 |
| 17 | -979816320 |
| 18 | -17642862720 |
| 19 | -17642862701 |
| 20 | -17642862340 |
| 21 | -17642854740 |
| 22 | -17642687160 |
| 23 | -17638824840 |
| 24 | -17545953600 |
| 25 | -15220134720 |
| 26 | 45348065280 |
| 27 | 1683112193280 |