cp's OEIS Frontend

A143072 A positive integer n is included if both the number of 0's and the number of 1's in the binary representation of n are powers of 2 (including being possibly 1).

%I A143072 #12 Sep 14 2014 16:10:32
%S A143072 2,4,5,6,9,10,12,16,23,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,
%T A143072 57,58,60,135,139,141,142,147,149,150,153,154,156,163,165,166,169,170,
%U A143072 172,177,178,180,184,195,197,198,201,202,204,209,210,212,216,225,226,228
%N A143072 A positive integer n is included if both the number of 0's and the number of 1's in the binary representation of n are powers of 2 (including being possibly 1).
%H A143072 Reinhard Zumkeller, <a href="/A143072/b143072.txt">Table of n, a(n) for n = 1..10000</a>
%F A143072 A209229(A000120(a(n))) * A209229(A023416(a(n))) = 1. - _Reinhard Zumkeller_, Sep 14 2014
%e A143072 34 in binary is 100010. This has 4 zeros and 2 ones. And since 4 and 2 are both powers of 2, 34 is included in the sequence.
%t A143072 p2Q[n_]:=And@@(IntegerQ[Log[2,#]]&/@DigitCount[n,2]); Select[Range[250], p2Q] (* _Harvey P. Dale_, Aug 20 2013 *)
%o A143072 (Haskell)
%o A143072 a143072 n = a143072_list !! (n-1)
%o A143072 a143072_list = filter ((== 1) . a209229 . a023416) a143071_list
%o A143072 -- _Reinhard Zumkeller_, Sep 14 2014
%Y A143072 Cf. A023416, A000120, A143070, A143071.
%Y A143072 Cf. A209229.
%K A143072 base,nonn,look
%O A143072 1,1
%A A143072 _Leroy Quet_, Jul 22 2008
%E A143072 Extended by _Ray Chandler_, Jun 20 2009