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 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 0 |
| 6 | 5 |
| 7 | 0 |
| 8 | 26 |
| 9 | 0 |
| 10 | 133 |
| 11 | 0 |
| 12 | 708 |
| 13 | 0 |
| 14 | 3860 |
| 15 | 0 |
| 16 | 21604 |
| 17 | 0 |
| 18 | 123266 |
| 19 | 0 |
| 20 | 715216 |
| 21 | 0 |
| 22 | 4206956 |
| 23 | 0 |
| 24 | 25032840 |
| 25 | 0 |
| 26 | 150413322 |
| 27 | 0 |
| 28 | 911379384 |
| 29 | 0 |
| 30 | 5562367173 |
| 31 | 0 |
| 32 | 34164355715 |
| 33 | 0 |
| 34 | 211015212580 |
| 35 | 0 |
| 36 | 1309815397995 |
| 37 | 0 |
| 38 | 8166460799097 |
| 39 | 0 |
| 40 | 51120054233490 |