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A157583
Half the number of length n integer sequences with sum zero and sum of squares 5202.
1
1, 3, 306, 19110, 1405335, 127596189, 10056226796, 714714066732, 47739604854315, 2926869332706055, 164336205885920178, 8620987583406297606, 434508999474316043459, 21294115220098361584440, 1014206441760046027667880
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,0,5202)/2.
CROSSREFS
Sequence in context: A052505 A307020 A071525 * A218361 A085319 A123032
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 02 2009
STATUS
approved