A366789 - OEIS

A366789

Fully multiplicative with a(p) = oddpart(primepi(p)).

1, 1, 1, 1, 3, 1, 1, 1, 1, 3, 5, 1, 3, 1, 3, 1, 7, 1, 1, 3, 1, 5, 9, 1, 9, 3, 1, 1, 5, 3, 11, 1, 5, 7, 3, 1, 3, 1, 3, 3, 13, 1, 7, 5, 3, 9, 15, 1, 1, 9, 7, 3, 1, 1, 15, 1, 1, 5, 17, 3, 9, 11, 1, 1, 9, 5, 19, 7, 9, 3, 5, 1, 21, 3, 9, 1, 5, 3, 11, 3, 1, 13, 23, 1, 21, 7, 5, 5, 3, 3, 3, 9, 11, 15, 3, 1, 25, 1, 5, 9

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OFFSET

1,5

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..52711

Index entries for sequences related to prime indices in the factorization of n

FORMULA

a(n) = A000265(A003963(n)).

MATHEMATICA

{1}~Join~Array[#/2^IntegerExponent[#, 2] &@ Apply[Times, PrimePi[#1]^#2 & @@@ FactorInteger[#]] &, 120, 2] (* Michael De Vlieger, Oct 23 2023 *)

PROG

(PARI)