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 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 8 |
| 6 | 22 |
| 7 | 61 |
| 8 | 169 |
| 9 | 468 |
| 10 | 1296 |
| 11 | 3589 |
| 12 | 9939 |
| 13 | 27524 |
| 14 | 76222 |
| 15 | 211081 |
| 16 | 584545 |
| 17 | 1618776 |
| 18 | 4482864 |
| 19 | 12414361 |
| 20 | 34378995 |
| 21 | 95205488 |
| 22 | 263651830 |
| 23 | 730128997 |
| 24 | 2021940649 |
| 25 | 5599344780 |
| 26 | 15506222688 |
| 27 | 42941263933 |
| 28 | 118916913891 |
| 29 | 329315700428 |
| 30 | 911971451326 |
| 31 | 2525515567441 |