A107285 a(n) = 5*401*(10^n + 1).

4010, 22055, 202505, 2007005, 20052005, 200502005, 2005002005, 20050002005, 200500002005, 2005000002005, 20050000002005, 200500000002005, 2005000000002005, 20050000000002005, 200500000000002005, 2005000000000002005, 20050000000000002005, 200500000000000002005

Offset: 0

Author

Reinhard Zumkeller, May 20 2005

Keywords

• nonn
• easy

Examples

			a(4) = 5*401*10001 = 20052005 = A106605(38).
		

Links

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

Crossrefs

Cf. A062397, A106605.

Programs

Mathematica

2005(10^Range[0,20]+1) (* or *) LinearRecurrence[{11,-10},{4010,22055},20] (* Harvey P. Dale, Sep 06 2016 *)

PARI

my(x='x+O('x^18)); Vec(2005*(2-11*x)/((10*x-1)*(x-1))) \\ Elmo R. Oliveira, Jun 16 2025

Formula

a(n) = 2005*A062397(n).

From Elmo R. Oliveira, Jun 16 2025: (Start)

G.f.: 2005*(2-11*x)/((1-x)*(1-10*x)).

E.g.f.: 2005*exp(x)*(1 + exp(9*x)).

a(n) = 10*a(n-1) - 18045.

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

Extensions

More terms from Elmo R. Oliveira, Jun 16 2025