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) |
|---|---|
| 5 | 1 |
| 6 | 30 |
| 7 | 595 |
| 8 | 9880 |
| 9 | 148995 |
| 10 | 2118760 |
| 11 | 28989675 |
| 12 | 386206920 |
| 13 | 5047381560 |
| 14 | 65033528560 |
| 15 | 828931106355 |
| 16 | 10477677064400 |
| 17 | 131567066917650 |
| 18 | 1643385429346680 |
| 19 | 20439879147794485 |
| 20 | 253338471349988640 |