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%I #4 Mar 31 2012 12:35:25
%S 1,3,6,6830,561735,29360121,1242596383,47858305311,1805644314360,
%T 65361758855305,2298374956416891,78740814179665443,
%U 2583344854373884146,80658838456091971635,2408249945284962451650,69283128843699421305698
%N Half the number of length n integer sequences with sum zero and sum of squares 2048.
%H R. H. Hardin, <a href="/A157564/b157564.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,0,2048)/2.
%K nonn
%O 2,2
%A _R. H. Hardin_ Mar 02 2009
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