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 | 18 |
| 5 | 139 |
| 6 | 1314 |
| 7 | 14658 |
| 8 | 188012 |
| 9 | 2721462 |
| 10 | 43837014 |
| 11 | 777266691 |
| 12 | 15037898091 |
| 13 | 315177210360 |
| 14 | 7112634073455 |
| 15 | 171930274269408 |
| 16 | 4431595775955999 |
| 17 | 121321383915646543 |
| 18 | 3515347574087951331 |
| 19 | 107474295428549047272 |