%I #6 Mar 31 2012 12:37:31
%S 57,42689,417014920,53276322556234,88975418528153598168,
%T 1942625963195375544523109688,554481819709548465938736952622972588,
%U 2069021570186779275218664788818854684235583075
%N 1/4 the number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having one, three or four distinct clockwise edge differences
%C Diagonal of A210156
%H R. H. Hardin, <a href="/A210148/b210148.txt">Table of n, a(n) for n = 1..9</a>
%e Some solutions for n=4
%e ..3..1..0..0..1....3..1..3..1..3....0..0..3..0..0....1..1..3..2..0
%e ..1..1..1..2..2....3..3..2..1..1....1..1..1..3..3....3..3..0..2..3
%e ..3..0..3..3..0....3..2..0..0..1....3..2..0..0..2....2..1..1..2..1
%e ..0..0..3..3..2....1..1..1..2..1....1..1..3..1..0....1..1..2..0..3
%e ..1..0..1..0..2....2..3..0..2..2....0..1..0..2..0....0..0..2..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 18 2012