A184010 - OEIS

%I #7 Mar 30 2012 18:57:13

%S 1,3,4,6,7,8,9,11,12,13,14,15,17,18,19,20,21,22,23,25,26,27,28,29,30,

%T 31,32,34,35,36,37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54,55,

%U 57,58,59,60,61,62,63,64,65,66,67,68,69,71,72,73,74,75,76,77,78,79,80,81,82,83,84,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,103,104,105,106,107,108,109,110,111

%N n + floor(sqrt(-1+4n/3)); complement of A001859 (except for initial zero).

%F a(n) = n + floor(sqrt(-1+4n/3))

%t   a=4/3; b=-1; Table[n+Floor[(a*n+b)^(1/2)],{n,100}]

%Y Cf. A001859.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jan 08 2011