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 | 1 |
| 3 | 5 |
| 4 | 14 |
| 5 | 94 |
| 6 | 444 |
| 7 | 3828 |
| 8 | 25584 |
| 9 | 270576 |
| 10 | 2342880 |
| 11 | 29400480 |
| 12 | 312888960 |
| 13 | 4546558080 |
| 14 | 57424792320 |
| 15 | 948550176000 |
| 16 | 13869128448000 |
| 17 | 256697973504000 |
| 18 | 4264876094976000 |
| 19 | 87435019510272000 |
| 20 | 1627055289796608000 |
| 21 | 36601063093905408000 |
| 22 | 754132445894209536000 |