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A088014
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E.g.f.: cosh(sqrt(2)x)(1+exp(x)).
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2
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2, 1, 5, 7, 21, 41, 107, 239, 593, 1393, 3395, 8119, 19665, 47321, 114371, 275807, 666113, 1607521, 3881411, 9369319, 22620561, 54608393, 131838371, 318281039, 768402497, 1855077841, 4478562275, 10812186007, 26102942481, 63018038201
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OFFSET
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0,1
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LINKS
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Table of n, a(n) for n=0..29.
Index to sequences with linear recurrences with constant coefficients, signature (2,3,-4,-2)
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FORMULA
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G.f.: (x-2)*(2*x-1)*(1+x) / ( (2*x^2-1)*(x^2+2*x-1) )
E.g.f. : cosh(sqrt(2)x)(1+exp(x)); a(n)=((sqrt(2))^n+(-sqrt(2))^n+(1+sqrt(2))^n+(1-sqrt(2))^n)/2.
a(0)=2, a(1)=1, a(2)=5, a(3)=7, a(n)=2*a(n-1)+3*a(n-2)-4*a(n-3)-2*a(n-4) -- From Harvey P. Dale, Jul 31 2012
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MATHEMATICA
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With[{nn=30}, CoefficientList[Series[Cosh[Sqrt[2]x](1+Exp[x]), {x, 0, nn}], x]Range[0, nn]!] (* or *) LinearRecurrence[{2, 3, -4, -2}, {2, 1, 5, 7}, 30] (* Harvey P. Dale, Jul 31 2012 *)
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CROSSREFS
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Cf. A052950.
Cf. A002315.
Sequence in context: A005297 A014551 A175002 * A193662 A175770 A141507
Adjacent sequences: A088011 A088012 A088013 * A088015 A088016 A088017
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KEYWORD
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easy,nonn
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AUTHOR
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Paul Barry, Sep 18 2003
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STATUS
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approved
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