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 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 119 |
| 6 | 694 |
| 7 | 4582 |
| 8 | 33325 |
| 9 | 261863 |
| 10 | 2192390 |
| 11 | 19358590 |
| 12 | 178904675 |
| 13 | 1720317763 |
| 14 | 17132629082 |
| 15 | 176055309619 |
| 16 | 1861037944163 |
| 17 | 20185165186517 |
| 18 | 224150069984572 |
| 19 | 2543698932578158 |
| 20 | 29451619807433107 |
| 21 | 347417296695040510 |
| 22 | 4170088041714300134 |
| 23 | 50874753262007210667 |