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%I #4 Mar 31 2012 12:35:25
%S 1,3,54,6710,552975,42285705,2331601391,101037868356,4170874974720,
%T 169800684016755,6716524310262195,256753303252023825,
%U 9424676123728329646,331044899193112524525,11129765080736905244370,360217055543666912443944
%N Half the number of length n integer sequences with sum zero and sum of squares 2592.
%H R. H. Hardin, <a href="/A157568/b157568.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,0,2592)/2.
%K nonn
%O 2,2
%A _R. H. Hardin_ Mar 02 2009
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