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 | 9 |
| 6 | 13 |
| 7 | 25 |
| 8 | 59 |
| 9 | 147 |
| 10 | 328 |
| 11 | 690 |
| 12 | 1478 |
| 13 | 3285 |
| 14 | 7357 |
| 15 | 16249 |
| 16 | 35561 |
| 17 | 77974 |
| 18 | 171891 |
| 19 | 379401 |
| 20 | 835954 |
| 21 | 1839288 |
| 22 | 4047688 |
| 23 | 8914186 |
| 24 | 19636159 |
| 25 | 43244340 |
| 26 | 95216488 |
| 27 | 209653186 |
| 28 | 461673635 |
| 29 | 1016681969 |
| 30 | 2238835524 |
| 31 | 4929989552 |