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 | 0 |
| 1 | 9 |
| 2 | 90 |
| 3 | 747 |
| 4 | 6660 |
| 5 | 59085 |
| 6 | 532350 |
| 7 | 4783023 |
| 8 | 43053480 |
| 9 | 387422001 |
| 10 | 3486843810 |
| 11 | 31381059699 |
| 12 | 282430082700 |
| 13 | 2541865828437 |
| 14 | 22876797238470 |
| 15 | 205891132215735 |
| 16 | 1853020231912080 |
| 17 | 16677181699666713 |
| 18 | 150094635685484490 |
| 19 | 1350851717672992251 |