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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 4 |
| 6 | 18 |
| 7 | 55 |
| 8 | 151 |
| 9 | 399 |
| 10 | 1061 |
| 11 | 2792 |
| 12 | 7252 |
| 13 | 18572 |
| 14 | 47051 |
| 15 | 118291 |
| 16 | 295718 |
| 17 | 735776 |
| 18 | 1823183 |
| 19 | 4501151 |
| 20 | 11077398 |
| 21 | 27187053 |
| 22 | 66567357 |
| 23 | 162655518 |
| 24 | 396728446 |
| 25 | 966109074 |
| 26 | 2349342360 |
| 27 | 5705883591 |
| 28 | 13842565488 |
| 29 | 33549053111 |
| 30 | 81238182806 |
| 31 | 196560818348 |