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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 516 |
| 3 | 19692 |
| 4 | 264208 |
| 5 | 1953150 |
| 6 | 10161072 |
| 7 | 40353656 |
| 8 | 135274560 |
| 9 | 387597717 |
| 10 | 1007825400 |
| 11 | 2357947812 |
| 12 | 5202783936 |
| 13 | 10604499542 |
| 14 | 20822486496 |
| 15 | 38461429800 |
| 16 | 69260574976 |
| 17 | 118587876786 |
| 18 | 200000421972 |
| 19 | 322687698140 |
| 20 | 516037855200 |
| 21 | 794644193952 |
| 22 | 1216701070992 |