A186233 - OEIS

%I #5 Mar 30 2012 17:22:57

%S 0,1,0,1,2,2,2,3,2,2,3,3,3,3,2,3,4,4,5,5,4,5,5,5,5,6,6,6,6,6,5,6,5,6,

%T 7,7,7,8,8,9,9,9,8,9,9,9,10,10,9,10,9,9,10,10,10,11,11,12,12,12,12,12,

%U 11,12,13,13,13,14,13,13,14,14,13,13,12,13,13,13,12,13,13,14,14,14,15,16,15,15,15,15,15,15,14,14,15,15,16,17,16,16

%N The number of lucky numbers between n and 2n, exclusive.

%C There is a lucky number between n and 2n for all n >= 4. There are at least n lucky numbers between x/2 and x for all x >= A186234(n).

%Y Cf. A000959 (lucky numbers)

%K nonn

%O 1,5

%A _T. D. Noe_, Feb 15 2011