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 | 10 |
| 2 | 80 |
| 3 | 580 |
| 4 | 3980 |
| 5 | 26380 |
| 6 | 170780 |
| 7 | 1087180 |
| 8 | 6835580 |
| 9 | 42575980 |
| 10 | 263268380 |
| 11 | 1618672780 |
| 12 | 9907349180 |
| 13 | 60420657580 |
| 14 | 367406757980 |
| 15 | 2228854610380 |
| 16 | 13495197974780 |
| 17 | 81581539411180 |
| 18 | 492540994279580 |
| 19 | 2970504754739980 |
| 20 | 17899322473752380 |