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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 15 |
| 6 | 71 |
| 7 | 428 |
| 8 | 3406 |
| 9 | 34270 |
| 10 | 418621 |
| 11 | 5937051 |
| 12 | 94782437 |
| 13 | 1670327647 |
| 14 | 32090011476 |
| 15 | 666351752261 |
| 16 | 14859579573845 |