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 | 5 |
| 4 | 15 |
| 5 | 50 |
| 6 | 185 |
| 7 | 737 |
| 8 | 3126 |
| 9 | 13976 |
| 10 | 65426 |
| 11 | 318699 |
| 12 | 1607800 |
| 13 | 8368088 |
| 14 | 44791046 |
| 15 | 245903077 |
| 16 | 1381505822 |
| 17 | 7926881015 |
| 18 | 46373681595 |
| 19 | 276193339071 |
| 20 | 1672469062126 |
| 21 | 10284954435831 |
| 22 | 64164864206704 |
| 23 | 405733694376937 |
| 24 | 2598199309906531 |
| 25 | 16837017409254863 |