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 | 15 |
| 3 | 2926 |
| 4 | 567645 |
| 5 | 110120220 |
| 6 | 21362755051 |
| 7 | 4144264359690 |
| 8 | 803965923024825 |
| 9 | 155965244802456376 |
| 10 | 30256453525753512135 |
| 11 | 5869596018751378897830 |
| 12 | 1138671371184241752666901 |
| 13 | 220896376413724148638480980 |