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 | 2 |
| 2 | 18 |
| 3 | 128 |
| 4 | 1590 |
| 5 | 19002 |
| 6 | 353304 |
| 7 | 6591776 |
| 8 | 154083654 |
| 9 | 3878583770 |
| 10 | 110647791078 |
| 11 | 3423740752764 |
| 12 | 116116072618104 |
| 13 | 4240251502692142 |
| 14 | 166761491097360240 |
| 15 | 7006327371058071648 |
| 16 | 313637735782416564806 |
| 17 | 14890324713956395361406 |
| 18 | 747610406539465959084870 |