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 | 10 |
| 6 | 66 |
| 7 | 365 |
| 8 | 1837 |
| 9 | 8741 |
| 10 | 40133 |
| 11 | 179932 |
| 12 | 793605 |
| 13 | 3460106 |
| 14 | 14961664 |
| 15 | 64306917 |
| 16 | 275180827 |
| 17 | 1173714565 |
| 18 | 4994096327 |
| 19 | 21211537533 |
| 20 | 89972566673 |
| 21 | 381261067469 |
| 22 | 1614446775255 |
| 23 | 6832832045575 |
| 24 | 28908094009481 |
| 25 | 122272843951891 |
| 26 | 517095189163181 |