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 A268762 Number of n X 4 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once. 1
 5, 44, 223, 1148, 5170, 23156, 99057, 418924, 1736105, 7122856, 28898144, 116346184, 465034573, 1848051516, 7306228767, 28758043956, 112751067666, 440538622908, 1715952146561, 6665380161836, 25826102521633, 99840968906384 (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) = 4*a(n-1) + 10*a(n-2) - 32*a(n-3) - 47*a(n-4) + 40*a(n-5) + 38*a(n-6) - 12*a(n-7) - 9*a(n-8). Empirical g.f.: x*(5 + 24*x - 3*x^2 - 24*x^3 - 9*x^4) / (1 - 2*x - 7*x^2 + 2*x^3 + 3*x^4)^2. - Colin Barker, Jan 14 2019 EXAMPLE Some solutions for n=4: ..1..0..0..0. .1..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..1..0 ..0..0..0..0. .0..0..1..1. .0..0..0..0. .1..0..0..0. .0..0..0..0 ..1..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..1..1 ..1..0..0..1. .1..0..0..1. .0..0..1..0. .0..0..0..1. .1..0..0..0 CROSSREFS Column 4 of A268766. Sequence in context: A128523 A271298 A271118 * A068311 A109984 A247776 Adjacent sequences: A268759 A268760 A268761 * A268763 A268764 A268765 KEYWORD nonn AUTHOR R. H. Hardin, Feb 13 2016 STATUS approved

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Last modified January 30 03:27 EST 2023. Contains 359939 sequences. (Running on oeis4.)