A117890 Numbers n such that number of non-leading 0's in binary representation of n divides n.

2, 4, 5, 6, 10, 11, 12, 13, 14, 16, 18, 22, 23, 24, 26, 27, 28, 29, 30, 36, 40, 42, 46, 47, 48, 54, 55, 58, 59, 60, 61, 62, 65, 75, 76, 78, 80, 84, 88, 90, 94, 95, 99, 100, 102, 104, 105, 108, 110, 111, 112, 114, 118, 119, 120, 122, 123, 124, 125, 126, 132, 140, 144, 145

Offset

1,1

Comments

Contains primes of A095078(n) as a subset. Intersection of a(n) with A049445(n) is A117891(n). - R. J. Mathar, Apr 03 2006

Links

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

Formula

a(n)<=A117891(n) - R. J. Mathar, Apr 03 2006

a(n) mod A023416(a(n)) = 0. - Reinhard Zumkeller, Nov 22 2007

Example

24 is 11000 in binary. This binary representation has three 0's and 3 divides 24. So 24 is in the sequence.

Prog

(C) #include <stdio.h> int main(int argc, char *argv[]) { for(int n=1; n< 500; n++) { int digs=0; int nshifted=n; while(nshifted) { digs += 1- nshifted & 1; nshifted >>= 1; } if ( digs) if( n % digs == 0 ) printf("%d, ", n); } } - R. J. Mathar, Apr 03 2006
(Haskell)
a117890 n = a117890_list !! (n-1)
a117890_list = [x | x <- [1..], let z = a023416 x, z > 0, mod x z == 0]
-- Reinhard Zumkeller, Mar 31 2015

Crossrefs

Cf. A049445, A117891.

Cf. A023416.

Sequence in context: A325558 A140779 A348937 * A108853 A257085 A334736

Adjacent sequences: A117887 A117888 A117889 * A117891 A117892 A117893

Keyword

easy,nonn

Author

Leroy Quet, Mar 30 2006

Extensions

More terms from R. J. Mathar, Apr 03 2006

Status

approved