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) |
|---|---|
| 4 | 1 |
| 5 | 3 |
| 6 | 17 |
| 7 | 136 |
| 8 | 2388 |
| 9 | 80890 |
| 10 | 5114079 |
| 11 | 573273505 |
| 12 | 113095167034 |
| 13 | 39582550575765 |
| 14 | 24908445793058442 |
| 15 | 28560405143495819079 |
| 16 | 60364410130177223014724 |
| 17 | 237403933018799958309530349 |
| 18 | 1750323137355778190158082029500 |
| 19 | 24333358813699371350715221107464003 |
| 20 | 640811613278752754485012443963579501421 |