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 | 11 |
| 3 | 0 |
| 4 | 20 |
| 5 | 80 |
| 6 | 231 |
| 7 | 579 |
| 8 | 2437 |
| 9 | 7507 |
| 10 | 26278 |
| 11 | 91622 |
| 12 | 316406 |
| 13 | 1091518 |
| 14 | 3805139 |
| 15 | 13166620 |
| 16 | 45743807 |
| 17 | 158968332 |
| 18 | 552175778 |
| 19 | 1918002602 |
| 20 | 6665774473 |
| 21 | 23158033370 |
| 22 | 80468332463 |
| 23 | 279615402191 |
| 24 | 971597706573 |
| 25 | 3376114511226 |
| 26 | 11731585710994 |