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A201538 Number of nX7 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

%I A201538 #7 Jul 22 2025 16:17:43
%S A201538 18,899,72811,9526987,1408677515,208164634003,28456420346436,
%T A201538 3505159734744220,387870239576486118,38812326822498760643,
%U A201538 3543738686502556683539,297838575975499416278867
%N A201538 Number of nX7 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
%C A201538 Column 7 of A201539
%H A201538 R. H. Hardin, <a href="/A201538/b201538.txt">Table of n, a(n) for n = 1..14</a>
%e A201538 Some solutions for n=3
%e A201538 ..0..0..0..0..0..0..0....0..0..0..0..1..1..1....0..0..1..1..1..2..2
%e A201538 ..0..1..1..1..1..1..2....0..0..0..1..1..2..2....1..1..2..2..2..1..2
%e A201538 ..1..1..1..2..2..2..2....2..2..2..0..0..1..1....2..2..0..0..0..1..2
%K A201538 nonn
%O A201538 1,1
%A A201538 _R. H. Hardin_ Dec 02 2011