A177079 a(n) = 5*(10^n - 3).

35, 485, 4985, 49985, 499985, 4999985, 49999985, 499999985, 4999999985, 49999999985, 499999999985, 4999999999985, 49999999999985, 499999999999985, 4999999999999985, 49999999999999985, 499999999999999985, 4999999999999999985, 49999999999999999985, 499999999999999999985

Offset: 1

Author

Vincenzo Librandi

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..300
• Index entries for linear recurrences with constant coefficients, signature (11,-10).

Crossrefs

Cf. A173833.

Programs

Magma

[5*(10^n-3): n in [1..35]];

Mathematica

Table[5*(10^n-3),{n,20}]; (* Alonso del Arte, Nov 15 2010 *)
LinearRecurrence[{11,-10},{35,485},20] (* Harvey P. Dale, Aug 20 2023 *)

PARI

a(n)=5*10^n-15 \\ Charles R Greathouse IV, Jun 04 2011

Formula

From Elmo R. Oliveira, Jun 12 2025: (Start)

G.f.: 5*x*(20*x+7)/((x-1)*(10*x-1)).

E.g.f.: 5*(2 - 3*exp(x) + exp(10*x)).

a(n) = 5*A173833(n).

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