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 | 1 |
| 7 | 4 |
| 8 | 14 |
| 9 | 45 |
| 10 | 135 |
| 11 | 391 |
| 12 | 1105 |
| 13 | 3067 |
| 14 | 8404 |
| 15 | 22806 |
| 16 | 61428 |
| 17 | 164495 |
| 18 | 438459 |
| 19 | 1164363 |
| 20 | 3082717 |
| 21 | 8141422 |
| 22 | 21457255 |
| 23 | 56455195 |
| 24 | 148323305 |
| 25 | 389213825 |
| 26 | 1020283146 |
| 27 | 2672225692 |
| 28 | 6993600748 |
| 29 | 18291536552 |
| 30 | 47814575243 |
| 31 | 124929304664 |
| 32 | 326280023426 |