cp's OEIS Frontend

A205250 Number of (n+1) X 4 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.

%I A205250 #8 Jun 11 2018 08:02:49
%S A205250 112,752,5212,36304,253072,1764364,12301024,85762192,597930556,
%T A205250 4168748272,29064349264,202635502636,1412766774400,9849754525648,
%U A205250 68672102130652,478779201937552,3338029812632080,23272612897409356
%N A205250 Number of (n+1) X 4 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.
%C A205250 Column 3 of A205255.
%H A205250 R. H. Hardin, <a href="/A205250/b205250.txt">Table of n, a(n) for n = 1..210</a>
%F A205250 Empirical: a(n) = 10*a(n-1) - 24*a(n-2) + 21*a(n-3) - 6*a(n-4).
%F A205250 Empirical g.f.: 4*x*(2 - 3*x)*(14 - 25*x + 10*x^2) / ((1 - x)*(1 - 9*x + 15*x^2 - 6*x^3)). - _Colin Barker_, Jun 11 2018
%e A205250 Some solutions for n=4:
%e A205250 ..0..0..1..1....0..1..1..1....1..0..1..1....1..1..0..1....1..1..0..1
%e A205250 ..1..0..0..0....1..1..0..1....1..0..0..1....0..1..1..1....0..1..0..1
%e A205250 ..0..0..1..1....1..0..0..1....1..1..1..1....1..1..0..0....1..1..0..1
%e A205250 ..0..1..1..0....1..1..1..1....0..0..0..1....0..1..1..1....0..1..0..1
%e A205250 ..1..1..0..0....1..0..0..1....0..1..0..1....0..0..1..0....1..1..0..1
%Y A205250 Cf. A205255.
%K A205250 nonn
%O A205250 1,1
%A A205250 _R. H. Hardin_, Jan 24 2012