OFFSET
1,1
COMMENTS
The sequence is obtained using Eratosthenes-like sieve for evil numbers.
a(10^2) = 4367, a(10^3) = 40247, a(10^4) = 407659, a(10^5) = 4434067. - Giovanni Resta, Mar 28 2013
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
evilQ[n_] := EvenQ@Total@IntegerDigits[n, 2]; okQ[n_] := evilQ[n] && ! PrimeQ[n] && Catch[Do[If[evilQ[d], Throw[False]], {d, Most@Rest@Divisors@n}]; True]; Select[Range@3000, okQ] (* Giovanni Resta, Mar 28 2013 *)
PROG
(PARI) isevil(n) = hammingweight(n) % 2 == 0;
noevildiv(n) = {fordiv(n, d, if ((d < n) && isevil(d), return (0)); ); 1; }
lista(nn) = {forcomposite(n=1, nn, if (isevil(n) && noevildiv(n), print1(n, ", ")); ); } \\ Michel Marcus, Feb 08 2016
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vladimir Shevelev, Mar 28 2013
STATUS
approved