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) |
|---|---|
| 3 | 1 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 2 |
| 10 | 17 |
| 11 | 51 |
| 12 | 175 |
| 13 | 827 |
| 14 | 3951 |
| 15 | 20428 |
| 16 | 115262 |
| 17 | 692851 |
| 18 | 4324011 |
| 19 | 29446302 |
| 20 | 211048631 |
| 21 | 1623253741 |
| 22 | 13109205113 |