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 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 2 |
| 8 | 35 |
| 9 | 707 |
| 10 | 11477 |
| 11 | 146428 |
| 12 | 1530906 |
| 13 | 13663758 |
| 14 | 107554370 |
| 15 | 764873164 |
| 16 | 5004170844 |
| 17 | 30537798974 |
| 18 | 175688807383 |
| 19 | 960958921848 |
| 20 | 5030916734826 |