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 | 12 |
| 3 | 63 |
| 4 | 316 |
| 5 | 1705 |
| 6 | 10446 |
| 7 | 73465 |
| 8 | 588232 |
| 9 | 5294817 |
| 10 | 52949170 |
| 11 | 582442201 |
| 12 | 6989308140 |
| 13 | 90861008017 |
| 14 | 1272054114982 |
| 15 | 19080811728105 |
| 16 | 305292987653776 |
| 17 | 5189980790119105 |
| 18 | 93419654222149722 |
| 19 | 1774973430220851577 |
| 20 | 35499468604417039540 |
| 21 | 745488840692757839601 |