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 | 3 |
| 4 | 13 |
| 5 | 66 |
| 6 | 367 |
| 7 | 2164 |
| 8 | 13293 |
| 9 | 84157 |
| 10 | 545270 |
| 11 | 3598244 |
| 12 | 24100375 |
| 13 | 163416748 |
| 14 | 1119592052 |
| 15 | 7738412716 |
| 16 | 53894849437 |
| 17 | 377851866954 |
| 18 | 2664570714233 |
| 19 | 18887568709788 |
| 20 | 134501247038230 |
| 21 | 961774761388430 |
| 22 | 6903072966224220 |