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) |
|---|---|
| 7 | 1 |
| 8 | 15 |
| 9 | 141 |
| 10 | 939 |
| 11 | 4971 |
| 12 | 21981 |
| 13 | 84351 |
| 14 | 287961 |
| 15 | 891564 |
| 16 | 2539756 |
| 17 | 6733764 |
| 18 | 16769916 |
| 19 | 39526524 |
| 20 | 88722756 |
| 21 | 190653804 |
| 22 | 393952284 |
| 23 | 785736369 |
| 24 | 1517620599 |
| 25 | 2846653381 |
| 26 | 5198360739 |
| 27 | 9261986019 |
| 28 | 16131790389 |
| 29 | 27513326919 |
| 30 | 46020006201 |