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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 17 |
| 3 | 145 |
| 4 | 1649 |
| 5 | 23441 |
| 6 | 399865 |
| 7 | 7957881 |
| 8 | 180997857 |
| 9 | 4631289697 |
| 10 | 131670338921 |
| 11 | 4117813225769 |
| 12 | 140486274499345 |
| 13 | 5192341564319313 |
| 14 | 206669931188282073 |
| 15 | 8813624820931402201 |
| 16 | 400922608851086766017 |
| 17 | 19377398675442025382081 |
| 18 | 991639882680576890150089 |