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A157555
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Half the number of length n integer sequences with sum zero and sum of squares 1058.
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1
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1, 3, 150, 5070, 182175, 5887791, 180232444, 5773910724, 178835952285, 4946264437455, 125256800641170, 2987737855296558, 68285219070825029, 1509200139206357640, 32387266774022554680, 675011623200542959496
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,2
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LINKS
| R. H. Hardin, Table of n, a(n) for n=2..50
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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,0,1058)/2.
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CROSSREFS
| Sequence in context: A181748 A118840 A111816 * A157578 A137802 A100203
Adjacent sequences: A157552 A157553 A157554 * A157556 A157557 A157558
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KEYWORD
| nonn
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AUTHOR
| R. H. Hardin (rhhardin(AT)att.net) Mar 02 2009
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