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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 64 |
| 5 | 441 |
| 6 | 3855 |
| 7 | 41464 |
| 8 | 533736 |
| 9 | 8071785 |
| 10 | 141351715 |
| 11 | 2829417276 |
| 12 | 64038928728 |
| 13 | 1624347614737 |
| 14 | 45822087138879 |
| 15 | 1427872211276376 |
| 16 | 48858282302548240 |
| 17 | 1826209988254883889 |
| 18 | 74216973833968292451 |
| 19 | 3265676709281560408780 |