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 | 6 |
| 2 | 48 |
| 3 | 414 |
| 4 | 3876 |
| 5 | 38946 |
| 6 | 416808 |
| 7 | 4722774 |
| 8 | 56379756 |
| 9 | 706236426 |
| 10 | 9250945008 |
| 11 | 126342991614 |
| 12 | 1794459834036 |
| 13 | 26445918969906 |
| 14 | 403610795535288 |
| 15 | 6367606516836774 |
| 16 | 103683034842399996 |
| 17 | 1739933892930544986 |
| 18 | 30052751213767045248 |
| 19 | 533635421576480845134 |
| 20 | 9730601644306627161156 |