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 | 0 |
| 4 | 4 |
| 5 | 14 |
| 6 | 104 |
| 7 | 594 |
| 8 | 3988 |
| 9 | 29188 |
| 10 | 227588 |
| 11 | 1983482 |
| 12 | 18398780 |
| 13 | 188210020 |
| 14 | 2030025592 |
| 15 | 23828759942 |
| 16 | 293948660282 |
| 17 | 3909402733418 |
| 18 | 54360500959634 |
| 19 | 806312590045382 |