A056533 - OEIS

%I #14 Jul 19 2015 09:03:52

%S 1,3,5,9,11,17,19,25,27,35,37,43,51,57,59,69,75,83,85,97,101,113,117,

%T 129,131,147,153,161,163,181,185,195,203,211,219,233,243,257,259,273,

%U 275,291,307,315,321,339,341,357,369,387,389,401,417,425,437,453,465

%N Even sieve: start with natural numbers, remove every 2nd term, remove every 4th term from what remains, remove every 6th term from what remains, etc.

%H <a href="/index/Si#sieve">Index entries for sequences generated by sieves</a>

%e Start with (1,2,3,4,5,6,7,8,9,10,11,12,....), remove every 2nd term to get (1,3,5,7,9,11,...), remove every 4th term to get (1,3,5,9,11,...), etc.

%t lst = Range@480; i = 2; While[i <= (len = Length[lst]), lst = Drop[lst, {i, len, i}]; i+=2]; lst (* _Robert G. Wilson v_, May 26 2006 *)

%Y After k-th round of sieve, A001147(k)/A000165(k) of natural numbers remain, declining slowly to zero.

%K nonn

%O 1,2

%A _Henry Bottomley_, Jun 19 2000