%I #4 Mar 31 2012 12:35:25
%S 1,9,162,3010,100035,3757383,119414988,3493064772,95851672965,
%T 2417802179815,55917688232274,1207875284200806,25067626930769059,
%U 505877445756815265,9921228112937485800,188795923012791958280
%N Half the number of length n integer sequences with sum zero and sum of squares 882.
%H R. H. Hardin, <a href="/A157553/b157553.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=(ts)/n, tt=ss+2*q*s+n*q^2; count(n,t,tt)=sum[i^2<=tt]{ count(n1,ti,tti^2) }. a(n)=count(n,0,882)/2.
%K nonn
%O 2,2
%A _R. H. Hardin_ Mar 02 2009
