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%I #5 Dec 05 2013 19:56:38
%S 1,1,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,6,6,6,
%T 6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,
%U 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9
%N Let f(n) = n - pi(n). Then a(n) = least number of steps such that f(f(...(n)))=1.
%e a(10) = 3, 10 ->6 ->3 ->1.
%e a(100) = 9.
%e f(100) =100-25 = 75, f(75) = 75-21= 54, f(54) = 54-16 = 38, f(38) = 38-12= 26, f(26) = 26-9 = 17, f(17) = 17-7 = 10, f(10) = 10-4 =6, f(6) = 6-3=3, f(3) = 3-2 =1.
%Y Cf. A025003.
%K nonn
%O 2,3
%A _Amarnath Murthy_, Dec 07 2003
%E Corrected and extended by Sam Handler (sam_5_5_5_0(AT)yahoo.com), Dec 11 2004