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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
OFFSET
1,1
LINKS
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: A366650 A271298 A271118 * A068311 A109984 A247776
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2016
STATUS
approved