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 | 1 |
| 3 | 2 |
| 4 | 10 |
| 5 | 130 |
| 6 | 11950 |
| 7 | 175850 |
| 8 | 749470 |
| 9 | 1181729 |
| 10 | 11435450 |
| 11 | 916821671 |
| 12 | 956613659 |
| 13 | 1136307905 |
| 14 | 46746179770 |
| 15 | 77887660577 |
| 16 | 635913760790 |
| 17 | 53903615484947 |
| 18 | 55988454554339 |
| 19 | 534479689454189 |
| 20 | 1956592840355065 |