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 | 4 |
| 3 | 28 |
| 4 | 268 |
| 5 | 3164 |
| 6 | 43672 |
| 7 | 682632 |
| 8 | 11834536 |
| 9 | 224283416 |
| 10 | 4597330748 |
| 11 | 101100605540 |
| 12 | 2370095338372 |
| 13 | 58924635472260 |
| 14 | 1546999678599872 |
| 15 | 42734731811302304 |
| 16 | 1238309697485975648 |
| 17 | 37538075865014728096 |