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Half the number of length n integer sequences with sum zero and sum of squares 6962.
1

%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