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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 11 |
| 6 | 71 |
| 7 | 372 |
| 8 | 2850 |
| 9 | 21121 |
| 10 | 191077 |
| 11 | 1793078 |
| 12 | 19037624 |
| 13 | 214051059 |
| 14 | 2628723267 |
| 15 | 34285658032 |
| 16 | 479609321326 |
| 17 | 7104125711717 |
| 18 | 111655209047393 |
| 19 | 1849927197690186 |
| 20 | 32289686161489668 |