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A173808 (7*10^n+11)/9 for n>0. 1
9, 79, 779, 7779, 77779, 777779, 7777779, 77777779, 777777779, 7777777779, 77777777779, 777777777779, 7777777777779, 77777777777779, 777777777777779, 7777777777777779, 77777777777777779, 777777777777777779 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..100

Index entries for linear recurrences with constant coefficients, signature (11,-10).

FORMULA

a(n) = 10*a(n-1)-11 with n>0, a(0)=2.

G.f.: x*(9-20*x)/((1-x)*(1-10*x)). - Vincenzo Librandi Jul 05 2012

a(n) = 11*a(n-1) -10*a(n-2). - Vincenzo Librandi, Jul 05 2012

MATHEMATICA

CoefficientList[Series[(9-20*x)/((1-x)*(1-10*x)), {x, 0, 30}], x] (* Vincenzo Librandi, Jul 05 2012 *)

PROG

(MAGMA) [(7*10^n+11)/9: n in [1..20]]; // Vincenzo Librandi Jul 05 2012

CROSSREFS

Cf. A093404.

Sequence in context: A254598 A083411 A181279 * A293723 A255807 A293916

Adjacent sequences:  A173805 A173806 A173807 * A173809 A173810 A173811

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Feb 25 2010

STATUS

approved

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Last modified July 17 20:45 EDT 2019. Contains 325109 sequences. (Running on oeis4.)