A199685 a(n) = 5*10^n + 1.

6, 51, 501, 5001, 50001, 500001, 5000001, 50000001, 500000001, 5000000001, 50000000001, 500000000001, 5000000000001, 50000000000001, 500000000000001, 5000000000000001, 50000000000000001, 500000000000000001, 5000000000000000001, 50000000000000000001, 500000000000000000001

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

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

Formula

a(n) = 3*A126109(n).

a(n) = 10*a(n-1) - 9.

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

G.f.: 3*(2-5*x)/((1-x)*(1-10*x)).

E.g.f.: exp(x)*(5*exp(9*x) + 1). - Elmo R. Oliveira, Sep 15 2024

Mathematica

LinearRecurrence[{11, -10}, {6, 51}, 30] (* Harvey P. Dale, Apr 06 2013 *)

Prog

(Magma) [5*10^n+1: n in [0..30]];
(PARI) a(n)=5*10^n+1 \\ Charles R Greathouse IV, Oct 16 2015

Crossrefs

Cf. A126109.

Sequence in context: A202754 A363112 A180901 * A225615 A002295 A369507

Adjacent sequences: A199682 A199683 A199684 * A199686 A199687 A199688

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 09 2011

Status

approved