A228503 Number of nX5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.
5, 11, 88, 358, 2002, 9528, 49101, 243118, 1228036, 6141239, 30865981, 154742849, 776765183, 3896668986, 19553995645, 98108834263, 492283814664, 2470048647138, 12393793010466, 62186850336292, 312029099308093, 1565635002686314
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..0..0..0..0....1..0..0..0..0....1..0..0..0..0....1..0..0..0..1 ..0..0..0..1..0....0..0..1..0..1....0..0..0..0..0....0..0..0..0..0 ..0..0..0..0..0....1..0..0..0..0....0..1..0..0..1....1..0..0..0..0 ..0..0..0..0..1....0..0..0..1..0....0..0..0..0..0....0..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 2*a(n-1) +16*a(n-2) +a(n-3) -27*a(n-4) +a(n-5) +4*a(n-6).
Empirical: g.f. -x*(5+x-14*x^2+x^3+2*x^4) / ( -1+2*x+16*x^2+x^3-27*x^4+x^5+4*x^6 ). - R. J. Mathar, Aug 25 2013
Comments