%I #4 Mar 31 2012 12:35:25
%S 1,3,354,35410,3079815,254391501,20017977868,1645049437956,
%T 130713839323245,9274041450918255,602446992143570574,
%U 36862449524697504786,2161188475320550751257,122528449769743353508305
%N Half the number of length n integer sequences with sum zero and sum of squares 6962.
%H R. H. Hardin, <a href="/A157591/b157591.txt">Table of n, a(n) for n=2..50</a>
%F [cache enabling] count(n,s,ss)->count(n,t,tt) where t=s mod n, q=(t-s)/n, tt=ss+2*q*s+n*q^2; count(n,t,tt)=sum[i^2<=tt]{ count(n-1,t-i,tt-i^2) }. a(n)=count(n,0,6962)/2.
%K nonn
%O 2,2
%A _R. H. Hardin_ Mar 02 2009