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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 22 |
| 6 | 92 |
| 7 | 426 |
| 8 | 2145 |
| 9 | 11589 |
| 10 | 66425 |
| 11 | 399682 |
| 12 | 2500037 |
| 13 | 16115347 |
| 14 | 106266473 |
| 15 | 712602272 |
| 16 | 4837372576 |
| 17 | 33128183406 |
| 18 | 228308233098 |
| 19 | 1580495251012 |
| 20 | 10976092266889 |
| 21 | 76398165848091 |
| 22 | 532614662149795 |
| 23 | 3717370694711130 |