A228659 Number of nX7 binary arrays with top left value 1 and no two ones adjacent horizontally, diagonally or antidiagonally.
13, 194, 3556, 62368, 1096624, 19236832, 337258048, 5910459096, 103561279328, 1814380139952, 31785935283840, 556837728488064, 9754730426036000, 170882696555044928, 2993497165464775680, 52439495408779417216
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..0..0..0..0..0..1....1..0..0..0..0..0..1....1..0..0..0..0..1..0 ..0..0..0..0..0..0..1....0..0..1..0..1..0..0....0..0..0..0..0..0..0 ..0..0..1..0..1..0..1....1..0..1..0..1..0..1....1..0..0..0..0..0..0 ..0..0..1..0..0..0..1....0..0..1..0..0..0..1....1..0..1..0..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 30*a(n-1) -226*a(n-2) -108*a(n-3) +4324*a(n-4) -1612*a(n-5) -27016*a(n-6) -2240*a(n-7) +50112*a(n-8) +20032*a(n-9) -16768*a(n-10) -4864*a(n-11) +2048*a(n-12)
Comments