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A175332 Numbers whose binary expansion is of the form 11+0* 2
3, 6, 7, 12, 14, 15, 24, 28, 30, 31, 48, 56, 60, 62, 63, 96, 112, 120, 124, 126, 127, 192, 224, 240, 248, 252, 254, 255, 384, 448, 480, 496, 504, 508, 510, 511, 768, 896, 960, 992, 1008, 1016, 1020, 1022, 1023, 1536, 1792, 1920, 1984, 2016, 2032, 2040, 2044 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also numbers n such that the set (2^j)%n consists only of the powers of two.

LINKS

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

Index entries for sequences related to binary expansion of n

PROG

(PARI)

is_11p0s(n)=

{ /* Return whether binary expansion has form 11+0* */

  local(b);

  if ( n<3, return(0) );

  b = binary( n/(2^valuation(n, 2) ) );

  if ( #b<2, return(0) );

  for (j=1, #b, if(b[j]==0, return(0) ) );

  return(1);

}

for (n=1, 2100, if (is_11p0s(n), print1(n, ", ") ) ); /* show terms */

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a175332 n = a175332_list !! (n-1)

a175332_list = f $ singleton 3 where

  f s = x : f (if even x then insert z s' else insert z $ insert (z+1) s')

        where z = 2*x; (x, s') = deleteFindMin s

-- Reinhard Zumkeller, Sep 24 2014

CROSSREFS

Cf. A023758, A007088.

Sequence in context: A144795 A077459 A048717 * A022434 A242666 A226228

Adjacent sequences:  A175329 A175330 A175331 * A175333 A175334 A175335

KEYWORD

easy,nonn

AUTHOR

Joerg Arndt, Apr 12 2010

STATUS

approved

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Last modified December 14 03:31 EST 2019. Contains 329978 sequences. (Running on oeis4.)