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Search: id:A157600
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| A157600 |
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Half the number of length n integer sequences with sum zero and sum of squares 9248. |
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+0
1
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| 1, 3, 102, 30030, 5399445, 596031513, 53828636911, 4407428497293, 353304900193680, 27176309595536035, 2030727740280136689, 147839184902264090742, 10306962174706523122706, 683847390057269455279395
(list; graph; listen)
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OFFSET
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2,2
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LINKS
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Ron 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,0,9248)/2.
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CROSSREFS
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Sequence in context: A037062 A157549 A157566 this_sequence A139908 A128070 A101780
Adjacent sequences: A157597 A157598 A157599 this_sequence A157601 A157602 A157603
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net) Mar 02 2009
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