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A198970 a(n) = 4*10^n-1. 1
3, 39, 399, 3999, 39999, 399999, 3999999, 39999999, 399999999, 3999999999, 39999999999, 399999999999, 3999999999999, 39999999999999, 399999999999999, 3999999999999999, 39999999999999999, 399999999999999999, 3999999999999999999 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

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

FORMULA

a(n) = 3*A097166(n).

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

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

G.f.: 3*(1 + 2*x)/(1 - 11*x + 10*x^2). - Vincenzo Librandi, Jan 03 2013

MATHEMATICA

CoefficientList[Series[3*(1 + 2*x)/(1 - 11*x + 10*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)

PROG

(MAGMA) [4*10^n-1 : n in [0..20]]

CROSSREFS

Sequence in context: A191468 A203243 A063035 * A014850 A341671 A328809

Adjacent sequences:  A198967 A198968 A198969 * A198971 A198972 A198973

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Nov 01 2011

STATUS

approved

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Last modified May 28 16:37 EDT 2022. Contains 354119 sequences. (Running on oeis4.)