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A147840
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a(n)=10*a(n-1)-8*a(n-2), a(0)=1, a(1)=8 .
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2
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1, 8, 72, 656, 5984, 54592, 498048, 4543744, 41453056, 378180608, 3450181632, 31476371456, 287162261504, 2619811643392, 23900818341888, 218049690271744, 1989290355982336, 18148506037649408, 165570737528635392
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*7^k . G.f.: (1-2x)/(1-10x+8*x^2).
a(n)= ((17+3*sqrt(17))/34)*(5+sqrt(17))^n + ((17-3*sqrt(17))/34)*(5-sqrt(17))^n [From Richard Choulet, Nov 20 2008]
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MATHEMATICA
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LinearRecurrence[{10, -8}, {1, 8}, 20] (* Harvey P. Dale, Dec 02 2021 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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