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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 11 |
| 5 | 146 |
| 6 | 1914 |
| 7 | 21741 |
| 8 | 222847 |
| 9 | 2177991 |
| 10 | 20706430 |
| 11 | 194021497 |
| 12 | 1803413614 |
| 13 | 16694681959 |
| 14 | 154292579858 |
| 15 | 1425648765821 |
| 16 | 13181528127233 |
| 17 | 122022749987917 |
| 18 | 1131306675851868 |