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 | 0 |
| 1 | 1 |
| 2 | 10 |
| 3 | 80 |
| 4 | 600 |
| 5 | 4400 |
| 6 | 32000 |
| 7 | 232000 |
| 8 | 1680000 |
| 9 | 12160000 |
| 10 | 88000000 |
| 11 | 636800000 |
| 12 | 4608000000 |
| 13 | 33344000000 |
| 14 | 241280000000 |
| 15 | 1745920000000 |
| 16 | 12633600000000 |
| 17 | 91417600000000 |
| 18 | 661504000000000 |
| 19 | 4786688000000000 |
| 20 | 34636800000000000 |