A004753 Numbers whose binary expansion contains 100.

4, 8, 9, 12, 16, 17, 18, 19, 20, 24, 25, 28, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 44, 48, 49, 50, 51, 52, 56, 57, 60, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 88, 89, 92, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000
• Index entries for 2-automatic sequences.

Crossrefs

Complement of A003754.

Subsequence of A247875.

Cf. A004748, A004749, A004750, A004752.

Programs

Haskell

a004753 n = a004753_list !! (n-1)
a004753_list = filter f [0..] where
   f 0 = False; f x = x `mod` 4 == 0 || f (x `div` 2)
-- Reinhard Zumkeller, Oct 27 2011

Mathematica

Select[Range[110],MemberQ[Partition[IntegerDigits[#,2],3,1],{1,0,0}]&] (* Harvey P. Dale, Mar 14 2014 *)

PARI

is(n)=n=binary(n);for(i=3,#n,if(n[i-2]&&!n[i]&&!n[i-1],return(1)));0 \\ Charles R Greathouse IV, Sep 24 2012

PARI

is(n)=while(n>3, if(bitand(n,7)==4, return(1)); n>>=1); 0 \\ Charles R Greathouse IV, Feb 11 2017

Formula

a(n) ~ n. - Charles R Greathouse IV, Sep 24 2012