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A247875
Numbers that are even or whose binary expansions contain one or more pairs of adjacent zeros when odd.
3
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
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
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