OFFSET
1,2
COMMENTS
LINKS
MATHEMATICA
a[n_] := Switch[FactorInteger[n][[;; , 2]], {2}, 1, {1}, 2, {1, 1}, 2, _, 0]; a[1] = 1; Array[a, 100] (* Amiram Eldar, Aug 29 2023 *)
PROG
(PARI)
A080339(n) = ((1==n)||isprime(n));
(Python)
from sympy import factorint
def A230594(n): return 0 if sum(f:=factorint(n).values())>2 else (1 if n==1 or max(f)==2 else 2) # Chai Wah Wu, Jul 23 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Oct 27 2013
STATUS
approved