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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
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*7^k . G.f.: (1-2x)/(1-10x+8*x^2).
a(n)=(1/2)*(5+sqrt(17))^n-(3/34)*sqrt(17)*[5-sqrt(17)]^n+(1/2)*[5-sqrt(17)]^n+(3/34)*[5 +sqrt(17)]^n*sqrt(17), with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Nov 18 2008]
a(n)= ((17+3*sqrt(17))/34)*(5+sqrt(17))^n + ((17-3*sqrt(17))/34)*(5-sqrt(17))^n [From Richard Choulet (richardchoulet(AT)yahoo.fr), Nov 20 2008]
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CROSSREFS
| Sequence in context: A156566 A055275 A155198 * A115970 A078995 A082414
Adjacent sequences: A147837 A147838 A147839 * A147841 A147842 A147843
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KEYWORD
| nonn
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AUTHOR
| Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 14 2008
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