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 | 2 |
| 3 | 4 |
| 4 | 38 |
| 5 | 132 |
| 6 | 420 |
| 7 | 1426 |
| 8 | 4834 |
| 9 | 16796 |
| 10 | 58688 |
| 11 | 208012 |
| 12 | 742636 |
| 13 | 2674384 |
| 14 | 9693976 |
| 15 | 35357670 |
| 16 | 129641774 |