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Search: id:A152167
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| A152167 |
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a(n)=-a(n-1)+3*a(n-2), n>1 ; a(0)=1, a(1)=-3 . |
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+0
7
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| 1, -3, 6, -15, 33, -78, 177, -411, 942, -2175, 5001, -11526, 26529, -61107, 140694, -324015, 746097, -1718142, 3956433, 9110859, 20980158, -48312735, 111253209, -256191414, 589951041, -1358525283, 3128378406, -7203954255, 16589089473
(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+x-3*x^2) . a(n)=(-1)^n*A105476(n+1) . a(n)=Sum{k, 0<=k<=n}A147703(n,k)*(-4)^k .
a(n)=(1/2)*{[(1/2)-(1/2)*sqrt(13)]^n+[(1/2)+(1/2)*sqrt(13)]^n}+(7/26)*sqrt(13)*{[(1/2)-(1/2)*sqrt(13)]^n-[(1/2)+(1/2) *sqrt(13)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Dec 01 2008]
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CROSSREFS
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Cf. A105476
Sequence in context: A117161 A006961 A034740 this_sequence A105476 A000599 A063832
Adjacent sequences: A152164 A152165 A152166 this_sequence A152168 A152169 A152170
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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 27 2008
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