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 | 1 |
| 2 | 7 |
| 3 | 40 |
| 4 | 239 |
| 5 | 1461 |
| 6 | 9076 |
| 7 | 57044 |
| 8 | 361711 |
| 9 | 2309467 |
| 10 | 14827487 |
| 11 | 95630272 |
| 12 | 619111172 |
| 13 | 4021011580 |
| 14 | 26187682024 |
| 15 | 170960159100 |
| 16 | 1118406332655 |
| 17 | 7330011083079 |
| 18 | 48119501497909 |
| 19 | 316354663355384 |
| 20 | 2082573599282359 |
| 21 | 13726029056757029 |
| 22 | 90565080767425744 |