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 | 0 |
| 2 | 0 |
| 3 | 10 |
| 4 | 190 |
| 5 | 2878 |
| 6 | 45738 |
| 7 | 820118 |
| 8 | 16764354 |
| 9 | 387371878 |
| 10 | 9999815254 |
| 11 | 285310965190 |
| 12 | 8916097744112 |
| 13 | 302875096191666 |
| 14 | 11112006785441430 |
| 15 | 437893890225741870 |
| 16 | 18446744073108471242 |
| 17 | 827240261884003157974 |
| 18 | 39346408075287462440142 |
| 19 | 1978419655660278243860198 |