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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 5 |
| 8 | 12 |
| 9 | 36 |
| 10 | 110 |
| 11 | 326 |
| 12 | 963 |
| 13 | 2964 |
| 14 | 9797 |
| 15 | 34818 |
| 16 | 130585 |
| 17 | 506996 |
| 18 | 2018454 |
| 19 | 8238737 |
| 20 | 34627390 |
| 21 | 150485325 |
| 22 | 677033911 |
| 23 | 3147372610 |
| 24 | 15066340824 |
| 25 | 74025698886 |
| 26 | 372557932434 |
| 27 | 1919196902205 |
| 28 | 10119758506626 |
| 29 | 54627382038761 |
| 30 | 301832813494746 |