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) |
|---|---|
| 3 | 1 |
| 4 | 15 |
| 5 | 165 |
| 6 | 1611 |
| 7 | 14805 |
| 8 | 131307 |
| 9 | 1138261 |
| 10 | 9713835 |
| 11 | 81968469 |
| 12 | 685888171 |
| 13 | 5702382933 |
| 14 | 47168678571 |
| 15 | 388580070741 |
| 16 | 3190523226795 |
| 17 | 26124382262613 |
| 18 | 213415462218411 |
| 19 | 1740019150443861 |
| 20 | 14162920013474475 |
| 21 | 115112250539595093 |
| 22 | 934419385591442091 |
| 23 | 7576722323539318101 |