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A154999
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a(n)=7*a(n-1)+42*a(n-2), n>2 ; a(0)=1, a(1)=1, a(2)=13 .
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2
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1, 1, 13, 133, 1477, 15925, 173509, 1883413, 20471269, 222402229, 2416608901, 26257155925, 285297665317, 3099884206069, 33681691385797, 365966976355477, 3976399872691813, 43205412115772725, 469446679463465221
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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FORMULA
| a(n+1)=Sum_{k, 0<=k<=n}A154929(n,k)*6^(n-k).
a(n)=(19/434)*sqrt(217)*{[(7/2)+(1/2)*sqrt(217)]^(n-1)-[(7/2)-(1/2)*sqrt(217)]^(n-1)} +(1/2)*{[(7/2)+(1/2)*sqrt(217)]^(n-1)+[(7/2)-(1/2)*sqrt(217)]^(n-1)}+(6/7)*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Jan 20 2009]
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CROSSREFS
| Sequence in context: A031138 A097166 A073556 * A132935 A132930 A130774
Adjacent sequences: A154996 A154997 A154998 * A155000 A155001 A155002
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KEYWORD
| nonn
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AUTHOR
| Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 18 2009
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EXTENSIONS
| More terms from Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 27 2009
Corrected by D. S. McNeil, Aug 20 2010
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