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 | 1 |
| 1 | 2 |
| 2 | 16 |
| 3 | 170 |
| 4 | 1696 |
| 5 | 15962 |
| 6 | 144496 |
| 7 | 1273610 |
| 8 | 11012416 |
| 9 | 93864122 |
| 10 | 791266576 |
| 11 | 6612607850 |
| 12 | 54878189536 |
| 13 | 452866803482 |
| 14 | 3719823438256 |
| 15 | 30436810578890 |
| 16 | 248242046141056 |
| 17 | 2019169299698042 |
| 18 | 16385984911571536 |
| 19 | 132716292890482730 |
| 20 | 1073129238309234976 |
| 21 | 8664826172771491802 |