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 A269007 Number of n X 4 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once. 1
 5, 36, 305, 2136, 14240, 91048, 566656, 3456320, 20760192, 123186784, 723791744, 4218132480, 24414483712, 140486492800, 804321836032, 4584741088256, 26032741150720, 147311358346752, 831044097026048, 4675403505475584 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 12*a(n-1) - 40*a(n-2) + 8*a(n-3) + 92*a(n-4) - 32*a(n-5) - 64*a(n-6) for n>7. Empirical g.f.: x*(5 - 24*x + 73*x^2 - 124*x^3 + 60*x^4 + 16*x^5 + 4*x^6) / (1 - 6*x + 2*x^2 + 8*x^3)^2. - Colin Barker, Jan 18 2019 EXAMPLE Some solutions for n=4: ..0..0..1..0. .1..0..1..0. .0..0..1..0. .0..1..0..0. .0..0..0..0 ..0..0..0..1. .1..0..0..0. .0..1..0..0. .0..1..0..1. .0..1..0..0 ..0..0..0..1. .0..1..0..1. .0..0..0..0. .1..0..0..0. .0..0..1..0 ..0..1..0..1. .0..0..0..0. .1..0..0..1. .0..0..0..1. .1..0..1..0 CROSSREFS Column 4 of A269011. Sequence in context: A255489 A091161 A135149 * A246510 A341961 A278576 Adjacent sequences:  A269004 A269005 A269006 * A269008 A269009 A269010 KEYWORD nonn AUTHOR R. H. Hardin, Feb 17 2016 STATUS approved

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Last modified June 30 03:34 EDT 2022. Contains 354913 sequences. (Running on oeis4.)