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 | 5 |
| 3 | 70 |
| 4 | 1610 |
| 5 | 51520 |
| 6 | 2112320 |
| 7 | 105616000 |
| 8 | 6231344000 |
| 9 | 423731392000 |
| 10 | 32627317184000 |
| 11 | 2805949277824000 |
| 12 | 266565181393280000 |
| 13 | 27722778864901120000 |
| 14 | 3132674011733826560000 |
| 15 | 382186229431526840320000 |
| 16 | 50066396055530016081920000 |
| 17 | 7009295447774202251468800000 |