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Search: id:A152239
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| A152239 |
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a(n)=-5*a(n-1)+7*a(n-2), n>1 ; a(0)=1, a(1)=-7 . |
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+0
4
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| 1, -7, 42, -259, 1589, -9758, 59913, -367871, 2258746, -13868827, 85155357, -522858574, 3210380369, -19711911863, 121032221898, -743144492531, 4562948015941, -280167515274422, 172024393748697, -105623922943439
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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G.f.: (1-2*x)/(1+5*x-7*x^2). a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*(-8)^k.
a(n)=(1/2)*{[ -(5/2)+(1/2)*sqrt(53)]^n+[ -(5/2)-(1/2)*sqrt(53)]^n}+(9/106)*sqrt(53)*{[ -(5/2)-(1/2)*sqrt(53)]^n -[ -(5/2)+(1/2)*sqrt(53)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Dec 12 2008]
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CROSSREFS
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Cf. A152163, A152166, A152167, A152174, A152185, A152223
Sequence in context: A033133 A082035 A127016 this_sequence A152240 A073506 A025593
Adjacent sequences: A152236 A152237 A152238 this_sequence A152240 A152241 A152242
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KEYWORD
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sign
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AUTHOR
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Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 30 2008
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