%I #6 Sep 02 2015 10:20:28
%S 0,0,1,2,3,3,4,5,6,6,7,8,9,9,10,11,12,12,13,14,15,16,16,17,18,19,19,
%T 20,21,22,22,23,24,25,25,26,27,28,29,29,30,31,32,32,33,34,35,35,36,37,
%U 38,38,39,40,41,42,42,43,44,45,45,46,47,48,48,49,50,51,51,52,53,54,55,55,56,57,58,58,59,60,61,61,62,63,64,64,65,66,67,67,68,69,70,71,71,72,73,74,74,75,76,77,77,78,79,80,80,81,82,83,84,84,85,86,87,87,88,89,90,90,91
%N Floor((3-sqrt(5))n).
%F a(n) = floor((3-sqrt(5))*n).
%t Table[Floor[(3-5^(1/2))n], {n,0,120}]
%o (PARI) a(n)=3*n-1-sqrtint(5*n^2) \\ _Charles R Greathouse IV_, Sep 02 2015
%K nonn,easy
%O 0,4
%A _Clark Kimberling_, Mar 08 2011