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 | 4 |
| 3 | 25 |
| 4 | 185 |
| 5 | 1495 |
| 6 | 12776 |
| 7 | 113534 |
| 8 | 1038535 |
| 9 | 9713905 |
| 10 | 92480570 |
| 11 | 893215584 |
| 12 | 8730601596 |
| 13 | 86198356180 |
| 14 | 858388634250 |
| 15 | 8611765147660 |
| 16 | 86958794304735 |
| 17 | 883103159075400 |
| 18 | 9013769253136005 |
| 19 | 92419535419392485 |
| 20 | 951446700812718515 |
| 21 | 9831013564639954705 |