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A202972 Number of n X n 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.

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%I A202972 #8 Jul 22 2025 16:54:40
%S A202972 1,2,17,385,31380,8071997,6330398606,15305115754880,
%T A202972 113359928263133320,2565928235760939767164,
%U A202972 177686302889022383527488349,37653160193950657089306550224687,24413727008012244865702150476410950284
%N A202972 Number of n X n 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
%C A202972 Diagonal of A202979
%e A202972 Some solutions for n=5
%e A202972 ..0..0..1..1..0....1..1..1..1..1....0..1..1..1..0....1..1..1..0..0
%e A202972 ..0..0..1..1..0....1..1..0..1..1....1..1..0..1..0....1..0..1..1..0
%e A202972 ..1..1..1..0..0....1..1..0..1..0....1..1..1..1..1....1..1..1..1..1
%e A202972 ..1..1..1..1..1....0..0..0..1..1....1..1..1..0..1....0..1..1..1..1
%e A202972 ..1..1..0..1..1....0..0..0..1..1....0..0..1..1..1....0..1..1..0..0
%K A202972 nonn
%O A202972 1,2
%A A202972 _R. H. Hardin_ Dec 26 2011

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