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 | 5 |
| 3 | 22 |
| 4 | 117 |
| 5 | 678 |
| 6 | 4162 |
| 7 | 26588 |
| 8 | 174925 |
| 9 | 1177158 |
| 10 | 8064854 |
| 11 | 56062804 |
| 12 | 394443458 |
| 13 | 2803490524 |
| 14 | 20098913252 |
| 15 | 145175116408 |
| 16 | 1055463627197 |
| 17 | 7717664983366 |
| 18 | 56720231324046 |
| 19 | 418757618733092 |
| 20 | 3104269959560566 |