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 | 4 |
| 4 | 365 |
| 5 | 11770 |
| 6 | 278455 |
| 7 | 5715094 |
| 8 | 108498285 |
| 9 | 1963243930 |
| 10 | 34404675635 |
| 11 | 589459538734 |
| 12 | 9933916068505 |
| 13 | 165358097339890 |
| 14 | 2726894329246815 |
| 15 | 44648990949187174 |
| 16 | 727080119853611525 |
| 17 | 11790570902483264650 |
| 18 | 190587735542474633995 |
| 19 | 3073193346666282232414 |