A173952 a(1)=32 and, for n > 1, a(n) = 9*a(n-1) + 32.

32, 320, 2912, 26240, 236192, 2125760, 19131872, 172186880, 1549681952, 13947137600, 125524238432, 1129718145920, 10167463313312, 91507169819840, 823564528378592, 7412080755407360, 66708726798666272, 600378541187996480

Offset: 1

Author

John W. Layman, Mar 03 2010

Keywords

• nonn
• easy

Comments

It appears that all terms of this sequence are also terms of A173951.

Also, it appears that a(n) has the base-3 representation 1,0,2^(2n-2),1,2 where 2^k denotes k consecutive 2's.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..400
• Index entries for linear recurrences with constant coefficients, signature (10, -9).

Crossrefs

Cf. A173951.

Programs

Magma

[4*(9^n-1): n in [1..20]]; // Vincenzo Librandi, Jul 05 2011

Mathematica

NestList[9#+32&,32,20] (* Harvey P. Dale, May 27 2012 *)

Formula

From R. J. Mathar, Mar 04 2010: (Start)

a(n) = 4*(9^n-1) = 4*A024101(n) = 10*a(n-1) - 9*a(n-2).

G.f.: 32*x/ ((9*x-1) * (x-1)). (End)