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A047854
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a(n)=T(6,n), array T given by A047848.
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5
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1, 2, 11, 92, 821, 7382, 66431, 597872, 5380841, 48427562, 435848051, 3922632452, 35303692061, 317733228542, 2859599056871, 25736391511832, 231627523606481, 2084647712458322
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| (9^n + 7)/8. - Ralf Stephan, Feb 14 2004
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). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 06 2009]
a(n)=9*a(n-1)-7 (with a(0)=1) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 06 2010]
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EXAMPLE
| For n=1, a(1)=9*1-7=2; n=2, a(2)=9*2-7=11; n=3, a(3)=9*11-7=92 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 06 2010]
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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 (zerinvarylajos(AT)yahoo.com), Mar 20 2008
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MATHEMATICA
| a = {}; ZZ = 1; Do[ZZ = ZZ + 3^(2x); AppendTo[a, ZZ], {x, 0, 17}]; a - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 03 2007
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CROSSREFS
| n-th difference of a(n), a(n-1), ..., a(0) is 8^(n-1) for n=1, 2, 3, ...
Sequence in context: A004677 A094955 A143870 * A122708 A005366 A068392
Adjacent sequences: A047851 A047852 A047853 * A047855 A047856 A047857
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KEYWORD
| nonn
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AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu)
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