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 A181257 Number of (n+2)X5 binary matrices with every 3X3 block having exactly four 1's 1
 906, 1684, 3190, 6360, 14974, 36244, 91122, 247372, 681262, 1906656, 5492470, 15919324, 46439466, 136964884, 405022630, 1200958440, 3576601774, 10663915684, 31832655522, 95194295452, 284820551902, 852619865136, 2554290632230 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A181262 LINKS R. H. Hardin, Table of n, a(n) for n=1..200 FORMULA Empirical: a(n)=4*a(n-1)-3*a(n-2)+36*a(n-3)-144*a(n-4)+108*a(n-5)-503*a(n-6)+2012*a(n-7)-1509*a(n-8)+3480*a(n-9)-13920*a(n-10)+10440*a(n-11)-12564*a(n-12)+50256*a(n-13)-37692*a(n-14)+22464*a(n-15)-89856*a(n-16)+67392*a(n-17)-15552*a(n-18)+62208*a(n-19)-46656*a(n-20) EXAMPLE Some solutions for 5X5 ..1..1..0..1..0....0..1..1..0..1....0..0..0..0..1....0..0..1..0..0 ..0..1..0..1..1....0..1..1..0..0....0..1..1..1..0....1..0..1..0..0 ..1..0..0..0..1....0..0..0..0..1....1..0..1..0..0....0..0..1..1..0 ..1..1..0..1..0....1..0..1..1..0....0..0..0..0..1....0..0..1..0..0 ..0..1..0..1..1....1..1..0..1..0....0..1..1..1..0....1..1..0..0..1 CROSSREFS Sequence in context: A235949 A330284 A330303 * A235242 A270446 A006917 Adjacent sequences:  A181254 A181255 A181256 * A181258 A181259 A181260 KEYWORD nonn AUTHOR R. H. Hardin Oct 10 2010 STATUS approved

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Last modified January 20 10:33 EST 2022. Contains 350472 sequences. (Running on oeis4.)