A198276 19*2^n-1.

18, 37, 75, 151, 303, 607, 1215, 2431, 4863, 9727, 19455, 38911, 77823, 155647, 311295, 622591, 1245183, 2490367, 4980735, 9961471, 19922943, 39845887, 79691775, 159383551, 318767103, 637534207, 1275068415, 2550136831, 5100273663, 10200547327, 20401094655

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (3,-2).

Formula

a(n+1) = 2*a(n) + 1.

G.f.: ( 18-17*x ) / ( (2*x-1)*(x-1) ). - R. J. Mathar, Oct 25 2011

a(n) + a(n-1)^2 = (a(n-1)+1)^2. - Vincenzo Librandi, Jun 11 2014

Example

a(2) = 19*2^2-1 = 75.

Maple

A198276:=n->19*2^n-1; seq(A198276(n), n=0..30); # Wesley Ivan Hurt, Jun 11 2014

Mathematica

19*2^Range[0, 30]-1 (* or *) LinearRecurrence[{3, -2}, {18, 37}, 40] (* Harvey P. Dale, Dec 18 2013 *)

Prog

(BASIC) for j = 0 to 30 : print str$((19*2^j)-1)+", "; : next j
(Magma) [19*2^n-1: n in [0..30]]; // Vincenzo Librandi, Oct 28 2011

Crossrefs

Cf. A086224, A110288.

Sequence in context: A041636 A212428 A195147 * A041640 A041642 A041644

Adjacent sequences: A198273 A198274 A198275 * A198277 A198278 A198279

Keyword

nonn,easy

Author

Jeremy Gardiner, Oct 23 2011

Status

approved