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A157594
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Half the number of length n integer sequences with sum zero and sum of squares 7688.
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1
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1, 9, 198, 29790, 4026105, 406849401, 33869423679, 2526809359383, 185063876167860, 12982668662313075, 884404700588788401, 58698938381426781945, 3731136219706944217260, 225710021147180429934270
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OFFSET
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2,2
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LINKS
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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,0,7688)/2.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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