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%I #10 Dec 19 2015 12:56:53
%S 5,7,9,10,13,14,18,19,20,26,27,28,35,36,38,40,47,51,52,54,56,63,70,72,
%T 75,76,80,81,89,93,94,102,104,107,108,112,119,121,125,126,133,139,140,
%U 143,144,149,150,152,159,160,161,162,167,177,178,181,186,187,188,191
%N Iterations of "n->n/2 if n even, n->3n-1 if n odd" (A001281) starting at these numbers reach 5.
%t it5Q[n_]:=Last[NestWhileList[If[EvenQ[#],#/2,3#-1]&,n,#!=5&,1,100]]==5; Select[Range[200],it5Q] (* _Harvey P. Dale_, May 09 2012 *)
%Y Cf. A037084, A039500-A039505.
%K nonn,easy
%O 1,1
%A _Christian G. Bower_, Feb 15 1999