A133577 a(n) = a(n-1) + 10*a(n-2) for n >= 2, a(0)=1, a(1)=2.

1, 2, 12, 32, 152, 472, 1992, 6712, 26632, 93752, 360072, 1297592, 4898312, 17874232, 66857352, 245599672, 914173192, 3370169912, 12511901832, 46213600952, 171332619272, 633468628792, 2346794821512, 8681481109432

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (1,10).

Formula

G.f.: (1+x)/(1-x-10*x^2).

a(n) = Sum_{k=0..n+1} A122950(n+1,k)*9^(n+1-k). - Philippe Deléham, Jan 08 2008

Mathematica

LinearRecurrence[{1, 10}, {1, 2}, 24] (* or *)
CoefficientList[Series[(1 + x)/(1 - x - 10 x^2), {x, 0, 23}], x] (* Michael De Vlieger, Jul 20 2017 *)

Crossrefs

Sequence in context: A000647 A358852 A363661 * A106185 A098203 A305330

Adjacent sequences: A133574 A133575 A133576 * A133578 A133579 A133580

Keyword

easy,nonn

Author

Philippe Deléham, Jan 03 2008

Status

approved