A381203 a(n) is the lcm of the elements of the set of bases and exponents in the prime factorization of n.

2, 3, 2, 5, 6, 7, 6, 6, 10, 11, 6, 13, 14, 15, 4, 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, 12, 14, 10, 51, 26, 53, 6, 55, 42, 57, 58, 59, 30, 61, 62, 42, 6, 65, 66, 67, 34, 69, 70, 71

Offset: 2

Author

Paolo Xausa, Feb 17 2025

Keywords

• nonn
• easy

Comments

Differs from A381201 at n = 16, 48, 64, 80, 112, 144, 162, 176, 192, ... = A381213.

Examples

			a(12) = 6 because 12 = 2^2*3^1, the set of these bases and exponents is {1, 2, 3} and lcm(1, 2, 3) = 6.
a(31500) = 210 because 31500 = 2^2*3^2*5^3*7^1, the set of these bases and exponents is {1, 2, 3, 5, 7} and lcm(1, 2, 3, 5, 7) = 210.
		

Links

• Paolo Xausa, Table of n, a(n) for n = 2..10000

Crossrefs

Cf. A381201, A381202, A381204, A381205, A381213.

Programs

Mathematica

A381203[n_] := LCM @@ Flatten[FactorInteger[n]];
Array[A381203, 100, 2]

PARI

a(n) = my(f=factor(n)); lcm(setunion(Set(f[,1]), Set(f[,2]))); \\ Michel Marcus, Feb 18 2025