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) |
|---|---|
| 6 | 3 |
| 7 | 18 |
| 8 | 122 |
| 9 | 655 |
| 10 | 3240 |
| 11 | 14531 |
| 12 | 61520 |
| 13 | 247381 |
| 14 | 958434 |
| 15 | 3598594 |
| 16 | 13180348 |
| 17 | 47274577 |
| 18 | 166642096 |
| 19 | 578750970 |
| 20 | 1984671466 |
| 21 | 6731351834 |
| 22 | 22612409886 |
| 23 | 75321920403 |
| 24 | 249028297179 |
| 25 | 817867225710 |
| 26 | 2670093233760 |
| 27 | 8670380548402 |