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 | 7 |
| 4 | 70 |
| 5 | 610 |
| 6 | 5551 |
| 7 | 49777 |
| 8 | 448540 |
| 9 | 4035220 |
| 10 | 36321901 |
| 11 | 326882347 |
| 12 | 2941985410 |
| 13 | 26477735830 |
| 14 | 238300021051 |
| 15 | 2144698993717 |
| 16 | 19302294530680 |
| 17 | 173720640014440 |
| 18 | 1563485792415001 |
| 19 | 14071372034879887 |