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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 3 |
| 7 | 31 |
| 8 | 298 |
| 9 | 2616 |
| 10 | 20346 |
| 11 | 140605 |
| 12 | 880737 |
| 13 | 5082279 |
| 14 | 27402524 |
| 15 | 139587885 |
| 16 | 677772953 |
| 17 | 3158930531 |
| 18 | 14212444473 |
| 19 | 62009204208 |
| 20 | 263350765116 |
| 21 | 1092085621098 |
| 22 | 4433596269478 |