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A268890 Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1

%I #4 Feb 15 2016 11:37:09

%S 0,235,2418,31956,317966,3283890,31427480,299524050,2777161184,

%T 25505113994,231143340184,2077724593805,18526267129268,

%U 164165431218906,1446558738555296,12686251671077220,110791183092125102

%N Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

%C Row 5 of A268886.

%H R. H. Hardin, <a href="/A268890/b268890.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +97*a(n-2) +116*a(n-3) -2923*a(n-4) -10986*a(n-5) +4951*a(n-6) +72992*a(n-7) +36740*a(n-8) -223968*a(n-9) -159382*a(n-10) +423052*a(n-11) +256370*a(n-12) -539504*a(n-13) -176570*a(n-14) +450908*a(n-15) +6166*a(n-16) -217920*a(n-17) +57416*a(n-18) +45120*a(n-19) -25021*a(n-20) +562*a(n-21) +2089*a(n-22) -388*a(n-23) -31*a(n-24) +14*a(n-25) -a(n-26)

%e Some solutions for n=4

%e ..1..1..0..1. .1..0..0..0. .1..0..1..1. .1..0..0..0. .1..0..1..0

%e ..0..1..0..1. .0..0..0..1. .1..0..0..0. .0..0..0..1. .1..0..0..0

%e ..0..1..0..0. .1..0..0..0. .1..0..0..0. .1..1..0..1. .0..0..1..1

%e ..0..0..0..1. .1..0..0..0. .0..0..0..0. .0..0..0..1. .1..0..0..1

%e ..0..1..0..0. .1..0..1..1. .0..0..0..1. .0..0..0..1. .0..0..0..0

%Y Cf. A268886.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 15 2016

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Last modified July 6 15:18 EDT 2024. Contains 374057 sequences. (Running on oeis4.)