OFFSET
1,2
COMMENTS
Differs from A252849 by having the terms 1, 256, 512, 768, 1280, ..., and not having the terms 64, 128, 144, 192, 288, ... .
Numbers whose maximum exponent in their unique factorization in terms of distinct "Fermi-Dirac primes" (A368781) is not a power of 4.
The asymptotic density of this sequence is Sum_{k>=1} (1/zeta(4^k) - 1/zeta(2^(2*k-1))) = 0.32005681814901480646... .
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
q[n_] := EvenQ[IntegerLength[Max[FactorInteger[n][[;; , 2]]], 2]]; q[1] = True; Select[Range[200], q]
PROG
(PARI) is(n) = if(n == 1, 1, !(#binary(vecmax(factor(n)[, 2])) % 2));
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Amiram Eldar, Aug 06 2024
STATUS
approved