A184235 - OEIS

%I #5 Mar 31 2012 12:35:58

%S 1,1,1,1,3,15,31,119,555,2138,9548,33391,136682,468971,1753525,

%T 5789709,19745186,63565260,203046061,638284176,1947963410,5979604119,

%U 17725544038,53252284414,155128241215,456635560332,1314718658955,3796821176997

%N Number of strings of numbers x(i=1..n) in 0..4 with sum i^2*x(i)^2 equal to n^2*16

%C Column 4 of A184240

%H R. H. Hardin, <a href="/A184235/b184235.txt">Table of n, a(n) for n = 1..39</a>

%e All solutions for n=5

%e ..2....0....0

%e ..1....0....0

%e ..2....4....0

%e ..4....4....0

%e ..2....0....4

%K nonn

%O 1,5

%A _R. H. Hardin_ Jan 10 2011