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 | 15852 |
| 5 | 173172 |
| 6 | 1887492 |
| 7 | 20578452 |
| 8 | 224138292 |
| 9 | 2441606532 |
| 10 | 26583605772 |
| 11 | 289455960492 |
| 12 | 3150796704012 |
| 13 | 34298615880372 |
| 14 | 373292253262692 |
| 15 | 4062873240668412 |
| 16 | 44214072776280252 |
| 17 | 481167126859845852 |
| 18 | 5235893033922430692 |
| 19 | 56975931806991140292 |
| 20 | 619957835069070600132 |
| 21 | 6745858105534183489092 |