login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A031449 Numbers n which in base 2 have two fewer 0's than 1's. 1
3, 11, 13, 14, 39, 43, 45, 46, 51, 53, 54, 57, 58, 60, 143, 151, 155, 157, 158, 167, 171, 173, 174, 179, 181, 182, 185, 186, 188, 199, 203, 205, 206, 211, 213, 214, 217, 218, 220, 227, 229, 230, 233, 234, 236, 241, 242, 244, 248, 543, 559, 567, 571, 573, 574 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

13 in binary is 1101, which has three 1's but only one 0, hence 13 is in the sequence.

14 in binary is 1110, which has three 1's but only one 0, hence 14 is in the sequence.

15 in binary is 1111, which has four 1's but no significant 0's, hence 15 is not in the sequence.

MATHEMATICA

Select[Range[700], DigitCount[#, 2, 0] == DigitCount[#, 2, 1] - 2 &] (* Vincenzo Librandi, Aug 24 2013 *)

CROSSREFS

Cf. A023416, A080791 (these two sequences are identical except for a(0), which is irrelevant for this sequence because 0 has no 1's).

Sequence in context: A254220 A119231 A177335 * A305859 A090260 A179522

Adjacent sequences:  A031446 A031447 A031448 * A031450 A031451 A031452

KEYWORD

nonn,easy,base

AUTHOR

Clark Kimberling

EXTENSIONS

More terms from Vincenzo Librandi, Aug 24 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 29 04:54 EDT 2020. Contains 338066 sequences. (Running on oeis4.)