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) |
|---|---|
| 2 | 1 |
| 3 | 7 |
| 4 | 38 |
| 5 | 191 |
| 6 | 935 |
| 7 | 4547 |
| 8 | 22166 |
| 9 | 108790 |
| 10 | 538668 |
| 11 | 2692996 |
| 12 | 13594954 |
| 13 | 69281309 |
| 14 | 356222591 |
| 15 | 1846781939 |
| 16 | 9647229202 |
| 17 | 50744420578 |
| 18 | 268591503348 |
| 19 | 1429730471552 |
| 20 | 7649564591070 |
| 21 | 41117462702680 |
| 22 | 221938325574492 |
| 23 | 1202501072716220 |