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) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 20 |
| 4 | 119 |
| 5 | 715 |
| 6 | 4523 |
| 7 | 30509 |
| 8 | 213343 |
| 9 | 1530983 |
| 10 | 11203550 |
| 11 | 83064263 |
| 12 | 620498643 |
| 13 | 4643259527 |
| 14 | 34592032908 |
| 15 | 254639722327 |
| 16 | 1832740718223 |
| 17 | 12680919388801 |
| 18 | 81678704122892 |
| 19 | 452951221016511 |
| 20 | 1574800035301944 |
| 21 | 8395299939524712 |
| 22 | 282240813012897282 |
| 23 | 4457697545906326118 |
| 24 | 58106920364272792945 |
| 25 | 693274802905577732102 |
| 26 | 7864635685729658131835 |