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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 12 |
| 8 | 39 |
| 9 | 136 |
| 10 | 529 |
| 11 | 2171 |
| 12 | 9368 |
| 13 | 41534 |
| 14 | 188942 |
| 15 | 874906 |
| 16 | 4115060 |
| 17 | 19602156 |
| 18 | 94419351 |
| 19 | 459183768 |
| 20 | 2252217207 |
| 21 | 11130545494 |
| 22 | 55382155396 |
| 23 | 277255622646 |
| 24 | 1395731021610 |
| 25 | 7061871805974 |
| 26 | 35896206800034 |
| 27 | 183241761631584 |