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 | 3 |
| 2 | 24 |
| 3 | 199 |
| 4 | 1776 |
| 5 | 16713 |
| 6 | 163429 |
| 7 | 1644852 |
| 8 | 16929576 |
| 9 | 177384877 |
| 10 | 1885842105 |
| 11 | 20292695751 |
| 12 | 220595817213 |
| 13 | 2418988309494 |
| 14 | 26726104358958 |
| 15 | 297226167487469 |
| 16 | 3324654200094495 |
| 17 | 37379224636055040 |
| 18 | 422182501323170275 |
| 19 | 4788001977121735326 |
| 20 | 54502930562354983641 |