OFFSET
1
COMMENTS
Characteristic function of "Fermi-Dirac primes", A050376.
LINKS
MATHEMATICA
a[n_] := Boole[n > 1 && Length[(f = FactorInteger[n])] == 1 && (e = f[[;; , 2]]) == 2^IntegerExponent[e, 2]]; Array[a, 100] (* Amiram Eldar, Nov 27 2020 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 16 2018
STATUS
approved