A140788 a(n) = 6*4^n + 2.

8, 26, 98, 386, 1538, 6146, 24578, 98306, 393218, 1572866, 6291458, 25165826, 100663298, 402653186, 1610612738, 6442450946, 25769803778, 103079215106, 412316860418, 1649267441666, 6597069766658, 26388279066626

Offset

0,1

Comments

Also 2*A140660.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5,-4).

Formula

From R. J. Mathar, Feb 07 2009: (Start)

a(n) = 5*a(n-1) - 4*a(n-2).

G.f.: 2(4-7x)/((1-x)(1-4x)). (End)

Mathematica

6*4^Range[0, 30]+2 (* or *) LinearRecurrence[{5, -4}, {8, 26}, 30] (* Harvey P. Dale, Apr 15 2019 *)

Prog

(Magma) [6*4^n+2: n in [0..30]]; // Vincenzo Librandi, Aug 08 2011

Crossrefs

Sequence in context: A357593 A173365 A261971 * A082573 A112645 A220713

Adjacent sequences: A140785 A140786 A140787 * A140789 A140790 A140791

Keyword

nonn,easy

Author

Paul Curtz, Jul 14 2008

Extensions

More terms from R. J. Mathar, Feb 07 2009

Status

approved