A327531 a(n) = 1 if the prime indices of n are relatively prime, otherwise a(n) = n.

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

Offset

1,3

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 whose prime indices are relatively prime are A289509. The maximum divisor of n that is 1 or whose prime indices are relatively prime is A327529(n).

Also the quotient of n over the maximum divisor of n that is 1 or whose prime indices are relatively prime.

Links

Table of n, a(n) for n=1..78.

Gus Wiseman, Sequences counting and encoding certain classes of multisets

Mathematica

Table[n/Max[Select[Divisors[n], #==1||GCD@@PrimePi/@First/@FactorInteger[#]==1&]], {n, 100}]

Crossrefs

See link for additional cross-references.

Cf. A000005, A112798, A281116, A289509.

Sequence in context: A155457 A274658 A274660 * A327514 A009001 A093178

Adjacent sequences: A327528 A327529 A327530 * A327532 A327533 A327534

Keyword

nonn

Author

Gus Wiseman, Sep 17 2019

Status

approved