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 | 2572306572 |
| 10 | 28295372292 |
| 11 | 311249095212 |
| 12 | 3423740047332 |
| 13 | 37661140520652 |
| 14 | 414272545727172 |
| 15 | 4556998002998892 |
| 16 | 50126978032987812 |
| 17 | 551396758362865932 |
| 18 | 6065364341991525252 |
| 19 | 66719007761906777772 |
| 20 | 733909085380974555492 |