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!)
A125495 Composite odious numbers. 2
4, 8, 14, 16, 21, 22, 25, 26, 28, 32, 35, 38, 42, 44, 49, 50, 52, 55, 56, 62, 64, 69, 70, 74, 76, 81, 82, 84, 87, 88, 91, 93, 94, 98, 100, 104, 110, 112, 115, 117, 118, 121, 122, 124, 128, 133, 134, 138, 140, 143, 145, 146, 148, 152, 155, 158, 161, 162, 164, 168, 171 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

49 is in the sequence since it is composite and base-2 representation (110001) has an odd number of 1's.

MAPLE

a:=proc(n) local n2: n2:=convert(n, base, 2): if add(n2[j], j=1..nops(n2)) mod 2 = 1 and isprime(n)=false then n else fi end: seq(a(n), n=2..210); # Emeric Deutsch, Jan 01 2007

MATHEMATICA

Select[Range[171], OddQ @ DigitCount[#, 2][[1]] && CompositeQ[#] &] (* Amiram Eldar, Dec 09 2019 *)

CROSSREFS

Intersection of A002808 (the composite numbers) and A000069 (odious numbers).

Sequence in context: A312255 A312256 A229937 * A246158 A312257 A312258

Adjacent sequences:  A125492 A125493 A125494 * A125496 A125497 A125498

KEYWORD

base,nonn

AUTHOR

Tanya Khovanova, Dec 27 2006

EXTENSIONS

More terms from Emeric Deutsch, Jan 01 2007

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 20 19:28 EDT 2020. Contains 337909 sequences. (Running on oeis4.)