A210149 - OEIS

%I #10 Jul 14 2018 15:35:13

%S 57,820,11783,169343,2433709,34976109,502659771,7223984325,

%T 103819625131,1492045676385,21442962225379,308167930976177,

%U 4428841159329331,63649173203875529,914735278099257547,13146135085198398465

%N 1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having one, three or four distinct clockwise edge differences.

%C Column 1 of A210156.

%H R. H. Hardin, <a href="/A210149/b210149.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 11*a(n-1) + 46*a(n-2) + 36*a(n-3) - 10*a(n-4) - 8*a(n-5).

%F Empirical g.f.: x*(57 + 193*x + 141*x^2 - 42*x^3 - 32*x^4) / (1 - 11*x - 46*x^2 - 36*x^3 + 10*x^4 + 8*x^5). - _Colin Barker_, Jul 14 2018

%e Some solutions for n=4:

%e   0 0   2 3   2 0   3 2   1 1   1 0   1 3   3 2   1 1   3 1

%e   1 0   3 0   3 0   3 0   2 2   0 0   1 3   3 1   3 1   3 1

%e   0 2   0 2   2 0   1 1   1 0   0 3   3 2   1 2   0 0   3 3

%e   1 3   1 3   3 1   1 1   0 3   1 3   1 3   0 2   1 0   3 1

%e   3 0   2 0   1 2   2 1   0 0   1 0   0 1   0 0   2 0   1 1

%Y Cf. A210156.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 18 2012