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A157597
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Half the number of length n integer sequences with sum zero and sum of squares 8450.
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2
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1, 9, 630, 48670, 4293525, 358348053, 32224041500, 2966406894648, 259556693304825, 20157653282906667, 1439903350550159550, 97064374251531230622, 6271845201623139087495, 391742584864070048279685
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history;
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OFFSET
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2,2
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LINKS
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R. H. Hardin, Table of n, a(n) for n=2..50
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FORMULA
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[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,0,8450)/2.
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CROSSREFS
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Sequence in context: A188423 A158881 A188394 * A211611 A210053 A128795
Adjacent sequences: A157594 A157595 A157596 * A157598 A157599 A157600
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin Mar 02 2009
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STATUS
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approved
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