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A112556
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Sums of squared terms in rows of triangle A112555.
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3
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1, 2, 2, 4, 10, 32, 112, 408, 1514, 5680, 21472, 81644, 311896, 1196132, 4602236, 17757184, 68680170, 266200112, 1033703056, 4020716124, 15662273840, 61092127492, 238582873476, 932758045124, 3650336341240, 14298633670932
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OFFSET
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0,2
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COMMENTS
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First differences form A072547 and equals the unsigned central terms of triangle A112555.
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LINKS
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Table of n, a(n) for n=0..25.
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FORMULA
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G.f.: ( 2*(1+x)/(1-x) + x/(1-4*x)^(1/2) )/(2+x).
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MATHEMATICA
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CoefficientList[Series[(2(1+x)/(1-x)+x/(1-4x)^(1/2))/(2+x), {x, 0, 30}], x] (* From Harvey P. Dale, May 26 2011 *)
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PROG
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(PARI) {a(n)=local(x=X+X*O(X^n)); polcoeff((2*(1+x)/(1-x)+x/(1-4*x)^(1/2))/(2+x), n, X)}
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CROSSREFS
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Cf. A112555, A072547.
Sequence in context: A132824 A078801 A002420 * A054100 A034165 A006181
Adjacent sequences: A112553 A112554 A112555 * A112557 A112558 A112559
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna, Sep 21 2005
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STATUS
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approved
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