A108213 a(0)=44; if n odd, a(n) = a(n-1)/2, otherwise a(n) = 4*a(n-1).

44, 22, 88, 44, 176, 88, 352, 176, 704, 352, 1408, 704, 2816, 1408, 5632, 2816, 11264, 5632, 22528, 11264, 45056, 22528, 90112, 45056, 180224, 90112, 360448, 180224, 720896, 360448, 1441792, 720896, 2883584, 1441792, 5767168, 2883584, 11534336, 5767168

Offset

0,1

Links

Table of n, a(n) for n=0..37.

Index entries for linear recurrences with constant coefficients, signature (0,2)

Formula

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

a(n) = 22 * 2^A028242(n). - Franklin T. Adams-Watters, Mar 29 2006

a(n) = 2a(n-2), a(0)=44, a(1)=22. G.f.: (44*x+88)/(1-2*x^2). - Ralf Stephan, Jul 16 2013

Mathematica

nxt[{n_, a_}]:={n+1, If[EvenQ[n], a/2, 4a]}; Transpose[NestList[nxt, {0, 44}, 40]] [[2]] (* or *) LinearRecurrence[{0, 2}, {44, 22}, 40] (* Harvey P. Dale, Feb 21 2015 *)

Crossrefs

Twice A108732. Same as A108732 with first two terms deleted. - Alexandre Wajnberg, Dec 27 2005

Sequence in context: A074174 A033977 A033364 * A158376 A036182 A109644

Adjacent sequences: A108210 A108211 A108212 * A108214 A108215 A108216

Keyword

nonn,easy

Author

Guadalupe Garcia (lugar3628(AT)sbcglobal.net), Jun 15 2005

Extensions

Explanation and more terms from N. J. A. Sloane, Aug 11 2005

Status

approved