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 | 1 |
| 2 | 70 |
| 3 | 780 |
| 4 | 11482 |
| 5 | 135040 |
| 6 | 1543862 |
| 7 | 16699380 |
| 8 | 175280570 |
| 9 | 1792874048 |
| 10 | 17990831182 |
| 11 | 177773616180 |
| 12 | 1735220375914 |
| 13 | 16769137076968 |
| 14 | 160740670148270 |
| 15 | 1530462874512756 |
| 16 | 14491157235576770 |
| 17 | 136575590461035368 |
| 18 | 1282229192334549022 |
| 19 | 11999276440029403356 |
| 20 | 111987255233226452770 |