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 | 1392 |
| 4 | 14352 |
| 5 | 146112 |
| 6 | 1476672 |
| 7 | 14860032 |
| 8 | 149160192 |
| 9 | 1494961152 |
| 10 | 14969766912 |
| 11 | 149818601472 |
| 12 | 1498911608832 |
| 13 | 14993469652992 |
| 14 | 149960817917952 |
| 15 | 1499764907507712 |
| 16 | 14998589445046272 |
| 17 | 149991536670277632 |
| 18 | 1499949220021665792 |
| 19 | 14999695320129994752 |
| 20 | 149998171920779968512 |