login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A125494 Composite evil numbers. 0
6, 9, 10, 12, 15, 18, 20, 24, 27, 30, 33, 34, 36, 39, 40, 45, 46, 48, 51, 54, 57, 58, 60, 63, 65, 66, 68, 72, 75, 77, 78, 80, 85, 86, 90, 92, 95, 96, 99, 102, 105, 106, 108, 111, 114, 116, 119, 120, 123, 125, 126, 129, 130, 132, 135, 136, 141, 142, 144, 147, 150, 153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..62.

EXAMPLE

12 is in the sequence since it is composite and base 2 representation (1100) has an even 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 = 0 and isprime(n)=false then n else fi end: seq(a(n), n=1..180); - Emeric Deutsch, Jan 01 2007

CROSSREFS

Cf. A001969 = evil numbers.

Sequence in context: A090428 A039725 A262362 * A177029 A105066 A048283

Adjacent sequences:  A125491 A125492 A125493 * A125495 A125496 A125497

KEYWORD

base,nonn

AUTHOR

Tanya Khovanova, Dec 27 2006

EXTENSIONS

Corrected and extended by 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified April 28 16:04 EDT 2017. Contains 285578 sequences.