cp's OEIS Frontend

A158582 Numbers with at least two zeros in their binary representation.

%I A158582 #16 Dec 24 2024 22:12:22
%S A158582 4,8,9,10,12,16,17,18,19,20,21,22,24,25,26,28,32,33,34,35,36,37,38,39,
%T A158582 40,41,42,43,44,45,46,48,49,50,51,52,53,54,56,57,58,60,64,65,66,67,68,
%U A158582 69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91
%N A158582 Numbers with at least two zeros in their binary representation.
%C A158582 Subsequence of A158581; complement of A089633; A023416(a(n))>1.
%C A158582 A265705(a(n),k) != A265705(a(n),a(n)-k) for at least one k <= a(n). - _Reinhard Zumkeller_, Dec 15 2015
%H A158582 R. Zumkeller, <a href="/A158582/b158582.txt">Table of n, a(n) for n = 1..10000</a>
%t A158582 Select[Range[100],DigitCount[#,2,0]>1&] (* _Harvey P. Dale_, Jan 19 2015 *)
%o A158582 (Haskell)
%o A158582 a158582 n = a158582_list !! (n-1)
%o A158582 a158582_list = [x | x <- [0..], a023416 x > 1]
%o A158582 -- _Reinhard Zumkeller_, Mar 31 2015
%o A158582 (Python)
%o A158582 def A158582(n):
%o A158582     def f(x):
%o A158582         c = n+(((l:=(x+1).bit_length())+1)*(l-2)>>1)
%o A158582         m = bin(x+1)[2:].find('0')
%o A158582         c += m if m>-1 else l
%o A158582         return c
%o A158582     m, k = n, f(n)
%o A158582     while m != k: m, k = k, f(k)
%o A158582     return m # _Chai Wah Wu_, Dec 24 2024
%Y A158582 Cf. A007088, A023416.
%Y A158582  Cf. A089633, A158581, A265705.
%K A158582 nonn
%O A158582 1,1
%A A158582 _Reinhard Zumkeller_, Apr 16 2009