A089648 Numbers whose numbers of zeros and ones in binary representation differ at most by 1.

0, 1, 2, 4, 5, 6, 9, 10, 12, 17, 18, 19, 20, 21, 22, 24, 25, 26, 28, 35, 37, 38, 41, 42, 44, 49, 50, 52, 56, 67, 69, 70, 71, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 88, 89, 90, 92, 97, 98, 99, 100, 101, 102, 104, 105, 106, 108, 112, 113, 114, 116, 120, 135, 139

Offset: 1

Author

Reinhard Zumkeller, Jan 02 2004

Keywords

• nonn
• base

Comments

A031443 is a subsequence; abs(A037861(a(n))) <= 1.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Digit Count
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A023416, A000120.

Cf. A037861, union of A031443, A031444 and A031448.

Programs

Haskell

a089648 n = a089648_list !! (n-1)
a089648_list = filter ((<= 1) . abs . a037861) [0..]
-- Reinhard Zumkeller, Mar 31 2015

Mathematica

Select[Range[0,7! ],Abs[DigitCount[ #,2,0]-DigitCount[ #,2,1]]<2 &] (* Vladimir Joseph Stephan Orlovsky, Feb 16 2010 *)