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 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 39 |
| 5 | 212 |
| 6 | 1232 |
| 7 | 7492 |
| 8 | 47082 |
| 9 | 303336 |
| 10 | 1992826 |
| 11 | 13299624 |
| 12 | 89912992 |
| 13 | 614474252 |
| 14 | 4238138216 |
| 15 | 29463047072 |
| 16 | 206234876287 |
| 17 | 1452319244772 |
| 18 | 10281935334928 |
| 19 | 73138728191724 |
| 20 | 522475643860940 |
| 21 | 3746698673538480 |
| 22 | 26961197787989220 |
| 23 | 194626504416928080 |