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 | 4581 |
| 8 | 33284 |
| 9 | 260847 |
| 10 | 2172454 |
| 11 | 19015582 |
| 12 | 173461305 |
| 13 | 1638327423 |
| 14 | 15939733122 |
| 15 | 159099927785 |
| 16 | 1623799173782 |
| 17 | 16900201391546 |
| 18 | 178967276844263 |
| 19 | 1924689980696921 |
| 20 | 20987593594256974 |
| 21 | 231734179050033660 |
| 22 | 2587835777992844938 |
| 23 | 29198736751160012102 |