A336965 a(n) is the product of the distinct prime numbers appearing in the prime tower factorization of n.

1, 2, 3, 2, 5, 6, 7, 6, 6, 10, 11, 6, 13, 14, 15, 2, 17, 6, 19, 10, 21, 22, 23, 6, 10, 26, 3, 14, 29, 30, 31, 10, 33, 34, 35, 6, 37, 38, 39, 30, 41, 42, 43, 22, 30, 46, 47, 6, 14, 10, 51, 26, 53, 6, 55, 42, 57, 58, 59, 30, 61, 62, 42, 6, 65, 66, 67, 34, 69, 70

Offset: 1

Author

Rémy Sigrist, Aug 09 2020

Keywords

• nonn

Comments

The prime tower factorization of a number is defined in A182318.

For any n > 0, a(n) is the product of the terms in n-th row of A336964.

Examples

			A001221(a(n)) = A115588(n) for any n > 1.
a(n) = A007947(A279513(n)).
a(n) = n iff n is squarefree (A005117).
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001221, A005117, A007947, A115588, A182318, A336964.

Programs

PARI

a(n) = { my (f=factor(n), v=vecprod(f[,1]~)); for (k=1, #f~, v=lcm(v, a(f[k,2]))); v }