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A047854 a(n) = T(6,n), array T given by A047848. 5
1, 2, 11, 92, 821, 7382, 66431, 597872, 5380841, 48427562, 435848051, 3922632452, 35303692061, 317733228542, 2859599056871, 25736391511832, 231627523606481, 2084647712458322 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

FORMULA

a(n) = (9^n + 7)/8. - Ralf Stephan, Feb 14 2004

From Philippe Deléham, Oct 06 2009: (Start)

a(0) = 1, a(1) = 2, a(n) = 10*a(n-1) - 9*a(n-2) for n > 1.

G.f.: (1 - 8x)/(1 - 10x + 9x^2). (End)

a(n) = 9*a(n-1) - 7 (with a(0)=1). - Vincenzo Librandi, Aug 06 2010

EXAMPLE

From Vincenzo Librandi, Aug 06 2010: (Start)

a(1) = 9*1 - 7 = 2;

a(2) = 9*2 - 7 = 11;

a(3) = 9*11 - 7 = 92. (End)

MAPLE

a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=9*a[n-1]+1 od: seq(a[n]+1, n=0..17); # Zerinvary Lajos, Mar 20 2008

MATHEMATICA

a = {}; ZZ = 1; Do[ZZ = ZZ + 3^(2x); AppendTo[a, ZZ], {x, 0, 17}]; a (* Zerinvary Lajos, Apr 03 2007 *)

CROSSREFS

n-th difference of a(n), a(n-1), ..., a(0) is 8^(n-1) for n=1, 2, 3, ...

Sequence in context: A266656 A094955 A143870 * A222080 A122708 A225623

Adjacent sequences:  A047851 A047852 A047853 * A047855 A047856 A047857

KEYWORD

nonn,changed

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified August 23 11:46 EDT 2017. Contains 290995 sequences.