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A228503 Number of nX5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally. 1
5, 11, 88, 358, 2002, 9528, 49101, 243118, 1228036, 6141239, 30865981, 154742849, 776765183, 3896668986, 19553995645, 98108834263, 492283814664, 2470048647138, 12393793010466, 62186850336292, 312029099308093, 1565635002686314 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 5 of A228506
LINKS
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
EXAMPLE
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
CROSSREFS
Sequence in context: A090518 A057726 A057727 * A128454 A368013 A188514
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 23 2013
STATUS
approved

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Last modified June 25 08:42 EDT 2024. Contains 373701 sequences. (Running on oeis4.)