A327514 Quotient of n over the maximum divisor of n that is 1, 2, or a nonprime number whose prime indices are pairwise coprime.

1, 1, 3, 1, 5, 1, 7, 1, 9, 1, 11, 1, 13, 1, 1, 1, 17, 3, 19, 1, 21, 1, 23, 1, 25, 1, 27, 1, 29, 1, 31, 1, 1, 1, 1, 3, 37, 1, 39, 1, 41, 3, 43, 1, 3, 1, 47, 1, 49, 5, 1, 1, 53, 9, 1, 1, 57, 1, 59, 1, 61, 1, 63, 1, 65, 1, 67, 1, 1, 1, 71, 3, 73, 1, 5, 1, 1, 3

Offset: 1

Author

Gus Wiseman, Sep 19 2019

Keywords

• nonn

Comments

A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. Numbers that are 1, 2, or a nonprime number whose prime indices are pairwise coprime are listed in A302696.

Examples

			The divisors of 72 that are 1, 2, or nonprime numbers whose prime indices are pairwise coprime are: {1, 2, 4, 6, 8, 12, 24}, so a(72) = 72/24 = 3.
		

Links

• Gus Wiseman, Sequences counting and encoding certain classes of multisets

Crossrefs

See link for additional cross-references.

Cf. A000005, A006530, A056239, A112798, A302569, A302696, A304711.

Programs

Mathematica

primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
Table[n/Max[Select[Divisors[n],#==1||CoprimeQ@@primeMS[#]&]],{n,100}]