A136615 - OEIS

%I #2 Mar 30 2012 17:34:23

%S 1,2,0,0,0,16,16,16,112,112,112,912,912,912,7280,7280,7280,58256,

%T 58256,58256,466032,466032,466032,3728272,3728272,3728272,29826160,

%U 29826160,29826160,238609296,238609296,238609296,1908874352,1908874352

%N Fold-switch-fold sequence defined by McFarlane and Withers for m=3: Let A(n) = If[Mod[A(n - 1), 2] == 0, A(n - 1)/2, (m - A(n - 1))2]; a(n)= If[ Mod[A(n - 1), 2] == 0, a(n - 1)/2, (Pi - a(n - 1))/2].

%D Cayanne McFarlane and Wm. Douglas Withers; Dynamical Systems and Irrational Angle Construction by Paper-Folding, American Mathematical Monthly, Volume 115, Number 4, 2008, page 356; http://www.maa.org/pubs/monthly_apr08_toc.html.

%F m=3,A(0)=1;a(1)=(m-1)/2; A(n) = If[Mod[A(n - 1), 2] == 0, A(n - 1)/2, (m - A(n - 1))2]; a(0) = Pi; a(1) = Pi; a(n)= If[ Mod[A(n - 1), 2] == 0, a(n - 1)/2, (Pi - a(n - 1))/2]; output=2^n*a(n)/Pi

%t Clear[A, m, n] m = 3; A[0] = 1; A[1] = (m - 1)/2; A[n_] := A[n] = If[Mod[A[n - 1], 2] == 0, A[n - 1]/2, (m - A[n - 1])2]; a[0] = Pi; a[1] = Pi; a[n_] := a[n] = If[ Mod[A[n - 1], 2] == 0, a[n - 1]/2, (Pi - a[n - 1])/2]; Table[2^n*a[n]/Pi, {n, 0, 50}]

%K nonn

%O 1,2

%A _Roger L. Bagula_, Mar 31 2008