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) |
|---|---|
| 2 | 1 |
| 3 | 9 |
| 4 | 150 |
| 5 | 1085 |
| 6 | 5283 |
| 7 | 20495 |
| 8 | 69007 |
| 9 | 212020 |
| 10 | 613633 |
| 11 | 1708508 |
| 12 | 4640978 |
| 13 | 12414802 |
| 14 | 32903418 |
| 15 | 86731043 |
| 16 | 227905816 |
| 17 | 597838223 |
| 18 | 1566763325 |
| 19 | 4103989113 |
| 20 | 10747219441 |
| 21 | 28140274566 |
| 22 | 73676929931 |
| 23 | 192894712070 |
| 24 | 505012447636 |
| 25 | 1322149114676 |
| 26 | 3461442847524 |
| 27 | 9062189100301 |