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Search: id:A155198
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| A155198 |
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a(n)=9*a(n-1)+a(n-2), n>2 ; a(0)=1, a(1)=8, a(2)=72 . |
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+0
1
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| 1, 8, 72, 656, 5976, 54440, 495936, 4517864, 41156712, 374928272, 3415511160, 31114528712, 283446269568, 2582130954824, 23522624862984, 214285754721680, 1952094417358104, 17783135510944616, 162000314015859648
(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-x-x^2)/(1-9*x-x^2).
a(n)=4*{[(9/2)-(1/2)*sqrt(85)]^(n-1)+[(9/2)+(1/2)*sqrt(85)]^(n-1)}+(36/85)*sqrt(85)*{[(9/2)+(1/2)*sqrt(85)]^(n-1)-[(9/2)-(1/2)*sqrt(85)]^(n-1)}+[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Jan 26 2009]
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CROSSREFS
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Sequence in context: A057091 A156566 A055275 this_sequence A147840 A115970 A078995
Adjacent sequences: A155195 A155196 A155197 this_sequence A155199 A155200 A155201
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KEYWORD
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nonn
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AUTHOR
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Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 21 2009
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