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 | 12 |
| 2 | 132 |
| 3 | 1452 |
| 4 | 15972 |
| 5 | 175692 |
| 6 | 1932612 |
| 7 | 21258732 |
| 8 | 233846052 |
| 9 | 2572306506 |
| 10 | 28295370840 |
| 11 | 311249071320 |
| 12 | 3423739697400 |
| 13 | 37661135713080 |
| 14 | 414272482302360 |
| 15 | 4556997189369240 |
| 16 | 50126967807537720 |
| 17 | 551396631852151800 |