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 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 EXAMPLE 12 is in the sequence since it is composite and its 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 PROG (PARI) isok(n) = (n>0) && !isprime(n) && !(hammingweight(n) % 2); \\ Michel Marcus, Mar 29 2019 CROSSREFS Intersection of A002808 (composite numbers) and A001969 (evil numbers). Cf. A027699 (evil primes). 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

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Last modified May 26 15:59 EDT 2019. Contains 323597 sequences. (Running on oeis4.)