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 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 50 |
| 5 | 289 |
| 6 | 1682 |
| 7 | 9801 |
| 8 | 57122 |
| 9 | 332929 |
| 10 | 1940450 |
| 11 | 11309769 |
| 12 | 65918162 |
| 13 | 384199201 |
| 14 | 2239277042 |
| 15 | 13051463049 |
| 16 | 76069501250 |
| 17 | 443365544449 |
| 18 | 2584123765442 |
| 19 | 15061377048201 |
| 20 | 87784138523762 |
| 21 | 511643454094369 |
| 22 | 2982076586042450 |
| 23 | 17380816062160329 |
| 24 | 101302819786919522 |