A233687 - OEIS

%I #8 Jun 14 2014 02:39:26

%S 1188,13324,145512,1723204,19588516,233101508,2662026560,31690526268,

%T 362156082980,4311121344720,49276352227832,586529116562772,

%U 6704848247564968,79798491078174100,912305401324724884

%N Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 10, and no two adjacent values equal.

%C Column 4 of A233691.

%H R. H. Hardin, <a href="/A233687/b233687.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +222*a(n-2) -895*a(n-3) -14806*a(n-4) +61290*a(n-5) +479263*a(n-6) -2067766*a(n-7) -8897249*a(n-8) +40799029*a(n-9) +102512949*a(n-10) -513857547*a(n-11) -760171900*a(n-12) +4350919810*a(n-13) +3628256006*a(n-14) -25577829290*a(n-15) -10454924632*a(n-16) +106480049675*a(n-17) +12586615989*a(n-18) -317308345201*a(n-19) +27167936641*a(n-20) +679221981450*a(n-21) -157201990004*a(n-22) -1040817140533*a(n-23) +351215509546*a(n-24) +1129423930543*a(n-25) -469396649218*a(n-26) -850891317254*a(n-27) +403441486513*a(n-28) +431368323585*a(n-29) -223830914820*a(n-30) -140453027219*a(n-31) +77851050483*a(n-32) +27476109266*a(n-33) -16042803856*a(n-34) -2950519700*a(n-35) +1797075893*a(n-36) +152255054*a(n-37) -93497323*a(n-38) -3429989*a(n-39) +1518688*a(n-40) +74280*a(n-41).

%e Some solutions for n=3:

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 14 2013