A177097 a(n) = 6*(10^n-5).

30, 570, 5970, 59970, 599970, 5999970, 59999970, 599999970, 5999999970, 59999999970, 599999999970, 5999999999970, 59999999999970, 599999999999970, 5999999999999970, 59999999999999970, 599999999999999970

Offset: 1

Author

Vincenzo Librandi

Keywords

• nonn
• easy

Comments

Apparently 30 times the entries of A067272. - R. J. Mathar, Aug 24 2011

Links

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

Crossrefs

Cf. A067272.

Programs

Mathematica

Join[{30,570},FromDigits/@(Join[{5},#,{7,0}]&/@Table[PadLeft[{},n,9], {n,20}])] (* or *) LinearRecurrence[{11,-10},{30,570},20] (* Harvey P. Dale, Oct 10 2011 *)

Formula

G.f.: 30*x*(1+8*x) / ( (10*x-1)*(x-1) ). - R. J. Mathar, Aug 24 2011

a(1)=30, a(2)=570, a(n)=11*a(n-1)-10*a(n-2). [Harvey P. Dale, Oct 10 2011]