%I #5 Mar 30 2012 18:50:25
%S 1,6,18,5,5,7,37,132,29,63,46,11,7,212,25,38,145,136,46,118,39,37,24,
%T 15,19,85,211,179,249,266,190,87,259,216,16,70,210,56,255,94,143,244,
%U 482,558,46,327,271,93,110,8,121,29,421,329,47,40,394,376,64,249,49,390,321
%N Number of steps to reach the first integer starting with prime(n+1)/prime(n) and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached.
%e a(4)=5 since A000040(4+1)/A000040(4)=11/7 -> 22/7 -> 88/7 -> 1144/7 -> 187616/7 -> 718381664.
%Y Cf. A073524, A000040.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Oct 04 2002
%E Extended by _Max Alekseyev_, Jul 28 2009
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