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 | 0 |
| 2 | 1 |
| 3 | 47 |
| 4 | 598 |
| 5 | 6432 |
| 6 | 65099 |
| 7 | 617230 |
| 8 | 5623596 |
| 9 | 50564448 |
| 10 | 454769425 |
| 11 | 4117771727 |
| 12 | 37607628932 |
| 13 | 346065253753 |
| 14 | 3204941467716 |
| 15 | 29844570139583 |
| 16 | 279238340750839 |
| 17 | 2623557157371147 |
| 18 | 24739954287457774 |
| 19 | 234057667276061521 |
| 20 | 2220819602560635754 |
| 21 | 21127269486018448842 |