

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
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OFFSET

1,1


LINKS

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


EXAMPLE

12 is in the sequence since it is composite and base2 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,changed


AUTHOR

Tanya Khovanova, Dec 27 2006


EXTENSIONS

Corrected and extended by Emeric Deutsch, Jan 01 2007


STATUS

approved



