cp's OEIS Frontend

A247875 Numbers that are even or whose binary expansions contain one or more pairs of adjacent zeros when odd.

%I A247875 #12 Aug 30 2015 10:36:20
%S A247875 0,2,4,6,8,9,10,12,14,16,17,18,19,20,22,24,25,26,28,30,32,33,34,35,36,
%T A247875 37,38,39,40,41,42,44,46,48,49,50,51,52,54,56,57,58,60,62,64,65,66,67,
%U A247875 68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,86
%N A247875 Numbers that are even or whose binary expansions contain one or more pairs of adjacent zeros when odd.
%C A247875 Complement of A247648; union of A004753 and A005843.
%H A247875 Reinhard Zumkeller, <a href="/A247875/b247875.txt">Table of n, a(n) for n = 1..10000</a>
%t A247875 Module[{upto=100,odds},odds=Select[Range[1,upto,2], SequenceCount[ IntegerDigits[#,2],{0,0}]>0&];Sort[Join[odds,Range[0,upto,2]]]] (* The program uses the SequenceCount function from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 30 2015 *)
%o A247875 (Haskell)
%o A247875 a247875 n = a247875_list !! (n-1)
%o A247875 a247875_list = filter (\x -> even x || f x) [0..] where
%o A247875    f x = x > 0 && (x `mod` 4 == 0 || f (x `div` 2))
%o A247875 (Python)
%o A247875 A247875_list = [n for n in range(10**3) if not n % 2 or '00' in bin(n)]
%o A247875 # _Chai Wah Wu_, Sep 26 2014
%Y A247875 Cf. A247648, A004753, A005843.
%K A247875 nonn
%O A247875 1,2
%A A247875 _Reinhard Zumkeller_, Sep 25 2014
%E A247875 Definition edited by _Chai Wah Wu_, Sep 26 2014
%E A247875 Definition clarified by _Harvey P. Dale_, Aug 30 2015