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) |
|---|---|
| 5 | 1 |
| 6 | 15 |
| 7 | 120 |
| 8 | 695 |
| 9 | 3285 |
| 10 | 13473 |
| 11 | 49730 |
| 12 | 169115 |
| 13 | 538440 |
| 14 | 1623660 |
| 15 | 4677121 |
| 16 | 12955065 |
| 17 | 34682730 |
| 18 | 90113220 |
| 19 | 227992870 |
| 20 | 563267203 |
| 21 | 1361992935 |
| 22 | 3229643480 |
| 23 | 7522847555 |
| 24 | 17237982025 |
| 25 | 38905739524 |
| 26 | 86585024910 |
| 27 | 190193593830 |
| 28 | 412712252535 |
| 29 | 885382820550 |
| 30 | 1879084411753 |