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A235675 Number of (n+1)X(4+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise.

%I A235675 #6 Jul 23 2025 08:43:55
%S A235675 742,15790,330840,6894210,143484144,2985166430,62100488254,
%T A235675 1291848133836,26873571586520,559034577488572,11629252189546650,
%U A235675 241916151493365248,5032432178704803216,104686575579504167834,2177730111458692702436
%N A235675 Number of (n+1)X(4+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise.
%C A235675 Column 4 of A235679
%H A235675 R. H. Hardin, <a href="/A235675/b235675.txt">Table of n, a(n) for n = 1..210</a>
%F A235675 Empirical: a(n) = 25*a(n-1) -56*a(n-2) -760*a(n-3) +1870*a(n-4) +9093*a(n-5) -19671*a(n-6) -53908*a(n-7) +96797*a(n-8) +165297*a(n-9) -249510*a(n-10) -263103*a(n-11) +342224*a(n-12) +215121*a(n-13) -241863*a(n-14) -95529*a(n-15) +88208*a(n-16) +23290*a(n-17) -16128*a(n-18) -2854*a(n-19) +1362*a(n-20) +136*a(n-21) -40*a(n-22)
%e A235675 Some solutions for n=2
%e A235675 ..0..1..0..0..0....1..1..1..1..0....1..1..0..0..0....0..1..0..0..0
%e A235675 ..1..1..0..1..1....0..0..0..0..0....1..0..0..1..1....0..0..1..1..1
%e A235675 ..1..1..0..0..1....0..1..1..1..1....0..0..1..0..0....0..0..0..0..0
%K A235675 nonn
%O A235675 1,1
%A A235675 _R. H. Hardin_, Jan 13 2014