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 | 18 |
| 2 | 360 |
| 3 | 6840 |
| 4 | 130302 |
| 5 | 2475720 |
| 6 | 47045520 |
| 7 | 893864520 |
| 8 | 16983555840 |
| 9 | 322687560618 |
| 10 | 6131066120640 |
| 11 | 116490256285320 |
| 12 | 2213314916460120 |
| 13 | 42052983412605480 |
| 14 | 799006685733239040 |
| 15 | 15181127028931412160 |
| 16 | 288441413566677788022 |
| 17 | 5480386857766875373560 |