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A157573
Half the number of length n integer sequences with sum zero and sum of squares 3362.
1
1, 3, 246, 17230, 1034445, 59305701, 3243926588, 185256960120, 10229264210745, 504340200498475, 22766981281651398, 968060807776968126, 39440547846380819957, 1553885734839506217555, 59443252831855326838200
OFFSET
2,2
LINKS
FORMULA
[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,0,3362)/2.
CROSSREFS
Sequence in context: A092799 A229690 A140163 * A082717 A157777 A318065
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 02 2009
STATUS
approved