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 | 0 |
| 5 | 1 |
| 6 | 3 |
| 7 | 6 |
| 8 | 52 |
| 9 | 148 |
| 10 | 1140 |
| 11 | 2306 |
| 12 | 30121 |
| 13 | 48476 |
| 14 | 478957 |
| 15 | 1762917 |
| 16 | 8601630 |
| 17 | 20789656 |
| 18 | 268188642 |
| 19 | 431583572 |
| 20 | 4685759111 |
| 21 | 15045763312 |
| 22 | 86991023001 |
| 23 | 190548007556 |
| 24 | 2526401808203 |
| 25 | 4873374476388 |
| 26 | 39199367162137 |