login
a(n) = n - floor( sqrt(prime(n) ) ).
0

%I #9 Dec 30 2023 16:28:04

%S 0,1,1,2,2,3,3,4,5,5,6,6,7,8,9,9,10,11,11,12,13,14,14,15,16,16,17,18,

%T 19,20,20,21,22,23,23,24,25,26,27,27,28,29,30,31,31,32,33,34,34,35,36,

%U 37,38,39,39,40,41,42,43,44,45,45,46,47,48,49,49,50,51,52,53,54,54,55

%N a(n) = n - floor( sqrt(prime(n) ) ).

%t Table[n - Floor[Sqrt[Prime[n]]], {n, 100}] (* _Wesley Ivan Hurt_, Apr 20 2023 *)

%K easy,nonn

%O 1,4

%A _Giovanni Teofilatto_, Mar 20 2005

%E Corrected and extended by _Ray Chandler_, May 18 2005