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 | 0 |
| 2 | 0 |
| 3 | 28 |
| 4 | 1668 |
| 5 | 25052 |
| 6 | 215448 |
| 7 | 1189868 |
| 8 | 5199888 |
| 9 | 18520572 |
| 10 | 56978440 |
| 11 | 155627304 |
| 12 | 388897892 |
| 13 | 894254904 |
| 14 | 1932504496 |
| 15 | 3945470564 |
| 16 | 7669533756 |
| 17 | 14291010972 |
| 18 | 25694009628 |
| 19 | 44662697948 |
| 20 | 75451394832 |
| 21 | 124066723008 |
| 22 | 199190308172 |