OFFSET
1
LINKS
FORMULA
Multiplicative with a(p^e) = A010060(e).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Product_{p prime} (1 + f(1/p)) = 0.87686263163054480657..., where f(x) = 1 - x + (1 - (1-x) * Product_{k>=0} (1-x^(2^k)))/2. - Amiram Eldar, Oct 27 2023
MATHEMATICA
a[n_] := If[AllTrue[FactorInteger[n][[;; , 2]], OddQ[DigitCount[#, 2, 1]] &], 1, 0]; Array[a, 100] (* Amiram Eldar, Jul 19 2022 *)
PROG
(PARI) A355825(n) = factorback(apply(e->(hammingweight(e)%2), factor(n)[, 2]));
KEYWORD
nonn,easy,mult
AUTHOR
Antti Karttunen, Jul 19 2022
STATUS
approved