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A340372
a(n) = 1 if n has no more than one odd prime factor to an odd power in its prime factorization, 0 otherwise.
2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0
OFFSET
1
FORMULA
a(n) = [A162642(A000265(n)) <= 1], where [ ] is the Iverson bracket.
For all n, a(n) >= A340363(n) >= A340373(n).
PROG
(PARI) A340372(n) = (2>(#select(t->(t%2), factor(n>>valuation(n, 2))[, 2]))); \\ After code in A285801.
CROSSREFS
Characteristic function of A285801.
Cf. also A340363, A340373.
Sequence in context: A296079 A354806 A340363 * A167850 A167851 A340369
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 06 2021
STATUS
approved