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

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, 37, 38, 39, 40, 41, 42, 44, 46, 48, 49, 50, 51, 52, 54, 56, 57, 58, 60, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 86

Offset

1,2

Comments

Complement of A247648; union of A004753 and A005843.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Mathematica

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 *)

Prog

(Haskell)
a247875 n = a247875_list !! (n-1)
a247875_list = filter (\x -> even x || f x) [0..] where
   f x = x > 0 && (x `mod` 4 == 0 || f (x `div` 2))
(Python)
A247875_list = [n for n in range(10**3) if not n % 2 or '00' in bin(n)]
# Chai Wah Wu, Sep 26 2014

Crossrefs

Cf. A247648, A004753, A005843.

Sequence in context: A227197 A285517 A003254 * A153184 A047412 A282760

Adjacent sequences: A247872 A247873 A247874 * A247876 A247877 A247878

Keyword

nonn

Author

Reinhard Zumkeller, Sep 25 2014

Extensions

Definition edited by Chai Wah Wu, Sep 26 2014

Definition clarified by Harvey P. Dale, Aug 30 2015

Status

approved