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A220387 Majority value maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to at least half of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array.

%I A220387 #6 Jul 23 2025 01:07:26
%S A220387 1,7,25,79,278,966,3362,11642,40375,140102,486191,1686966,5853300,
%T A220387 20309556,70470311,244518242,848429087,2943877082,10214660764,
%U A220387 35442822154,122979474647,426714063696,1480612045993,5137426278616
%N A220387 Majority value maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to at least half of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array.
%C A220387 Row 2 of A220386
%H A220387 R. H. Hardin, <a href="/A220387/b220387.txt">Table of n, a(n) for n = 1..210</a>
%F A220387 Empirical: a(n) = 3*a(n-1) +4*a(n-3) +7*a(n-4) -7*a(n-6) -19*a(n-7) -21*a(n-8) -33*a(n-9) -14*a(n-10) +a(n-11) +6*a(n-12) +45*a(n-13) +27*a(n-14) +72*a(n-15) -a(n-16) +6*a(n-17) -32*a(n-18) -16*a(n-19) -4*a(n-20) +4*a(n-22)
%e A220387 Some solutions for n=3
%e A220387 ..1..0..0....1..1..1....0..0..0....0..0..1....0..0..1....0..0..1....1..1..0
%e A220387 ..0..0..1....1..0..0....1..1..1....0..0..0....0..1..1....1..1..1....1..1..1
%K A220387 nonn
%O A220387 1,2
%A A220387 _R. H. Hardin_ Dec 13 2012