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A003951
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G.f.: (1+x)/(1-8*x).
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56
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1, 9, 72, 576, 4608, 36864, 294912, 2359296, 18874368, 150994944, 1207959552, 9663676416, 77309411328, 618475290624, 4947802324992, 39582418599936, 316659348799488, 2533274790395904, 20266198323167232, 162129586585337856, 1297036692682702848
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OFFSET
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0,2
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COMMENTS
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Coordination sequence for infinite tree with valency 9.
Binomial transform is {1, 10, 91, 820, 7381, ...}, see A002452 . - Philippe DELEHAM, Jul 22 2005
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 0..1000
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 310
Index to divisibility sequences
Index to sequences with linear recurrences with constant coefficients, signature (8).
Index entries for sequences related to trees
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FORMULA
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a(n) = Sum_{ 0<=k<=n } A029653(n, k)*x^k for x = 7 . - Philippe DELEHAM, Jul 10 2005
a(0)=1; for n>0, a(n)=9*8^(n-1). - Vincenzo Librandi, Nov 18 2010]
a(0)=1, a(1)=9, a(n) = 8*a(n-1). - Vincenzo Librandi, Dec 10 2012
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MAPLE
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k := 9; if n = 0 then 1 else k*(k-1)^(n-1); fi;
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MATHEMATICA
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q = 9; Join[{a = 1}, Table[If[n != 0, a = q*a - a, a = q*a], {n, 0, 25}]] (* and *) Join[{1}, 9*8^Range[0, 25]] (* From Vladimir Joseph Stephan Orlovsky, Jul 11 2011 *)
CoefficientList[Series[(1 + x)/(1 - 8*x), {x, 0, 40}], x] (* Vincenzo Librandi, Dec 10 2012 *)
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PROG
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(MAGMA) [1] cat [9*8^(n-1): n in [1..20]]; // Vincenzo Librandi, Dec 11 2012
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CROSSREFS
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Sequence in context: A170594 A170642 A170690 * A033135 A127053 A001809
Adjacent sequences: A003948 A003949 A003950 * A003952 A003953 A003954
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane.
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EXTENSIONS
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Edited by N. J. A. Sloane, Dec 04 2009.
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STATUS
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approved
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