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 | 6 |
| 3 | 84 |
| 4 | 420 |
| 5 | 26040 |
| 6 | 78120 |
| 7 | 9921240 |
| 8 | 168661080 |
| 9 | 24624517680 |
| 10 | 270869694480 |
| 11 | 554470264600560 |
| 12 | 7208113439807280 |
| 13 | 59041657185461430480 |
| 14 | 2538791258974841510640 |
| 15 | 383357480105201068106640 |
| 16 | 98522872387036674503406480 |
| 17 | 25826982813282567927671981480160 |