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Search: id:A154997
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| A154997 |
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a(n)=6*a(n-1)+30*a(n-2), n>2 ; a(0)=1, a(1)=1, a(2)=11 . |
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+0
3
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| 1, 1, 11, 96, 906, 8316, 77076, 711936, 6583896, 60861456, 562685616, 5201957376, 48092312736, 444612597696, 4110444968256, 38001047740416, 351319635490176, 3247949245153536, 30027284535626496, 277602184568365056
(list; graph; listen)
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OFFSET
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0,3
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FORMULA
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G.f.: (1-5*x-25*x^2)/(1-6*x-30*x^2). a(n+1)=Sum_{k, 0<=k<=n}A154929(n,k)*5^(n-k).
a(n)=(4/39)*sqrt(39)*{[3+sqrt(39)]^(n-1)-[3-sqrt(39)]^(n-1)}+(1/2)*{[3+sqrt(39)]^(n-1)+[3-sqrt(39)]^(n-1)}+(5/6)*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Jan 20 2009]
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CROSSREFS
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Sequence in context: A055286 A081041 A115351 this_sequence A137017 A133833 A142260
Adjacent sequences: A154994 A154995 A154996 this_sequence A154998 A154999 A155000
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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 18 2009
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