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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 48 |
| 5 | 232 |
| 6 | 1207 |
| 7 | 6631 |
| 8 | 37998 |
| 9 | 225182 |
| 10 | 1371560 |
| 11 | 8546760 |
| 12 | 54294880 |
| 13 | 350658336 |
| 14 | 2297296991 |
| 15 | 15239785151 |
| 16 | 102218278626 |
| 17 | 692361482818 |
| 18 | 4730891905450 |
| 19 | 32581995322522 |
| 20 | 226000929559056 |
| 21 | 1577824515023456 |
| 22 | 11080975421752488 |
| 23 | 78244477268207656 |