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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 232 |
| 10 | 1452 |
| 11 | 6494 |
| 12 | 25286 |
| 13 | 90304 |
| 14 | 307450 |
| 15 | 1014007 |
| 16 | 3287295 |
| 17 | 10616111 |
| 18 | 34460913 |
| 19 | 112044376 |
| 20 | 364112828 |
| 21 | 1180542604 |
| 22 | 3814897196 |
| 23 | 12278519104 |
| 24 | 39353932208 |
| 25 | 125637022720 |
| 26 | 399749617604 |
| 27 | 1268585240868 |
| 28 | 4017417046988 |
| 29 | 12700795616136 |