A088835 a(n) = lcm(A020639(n), A006530(n)).

1, 2, 3, 2, 5, 6, 7, 2, 3, 10, 11, 6, 13, 14, 15, 2, 17, 6, 19, 10, 21, 22, 23, 6, 5, 26, 3, 14, 29, 10, 31, 2, 33, 34, 35, 6, 37, 38, 39, 10, 41, 14, 43, 22, 15, 46, 47, 6, 7, 10, 51, 26, 53, 6, 55, 14, 57, 58, 59, 10, 61, 62, 21, 2, 65, 22, 67, 34, 69, 14, 71, 6, 73, 74, 15, 38, 77

Offset: 1

Author

Labos Elemer, Oct 31 2003

Keywords

• nonn

Links

• Enrique Pérez Herrero, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A020639, A006530, A066048, A007947, A062953, A015052, A015053, A053166, A097448.

Programs

Mathematica

Map[LCM[#[[1,1]], #[[-1,1]]] &, FactorInteger[Range[100]]] (* Paolo Xausa, Mar 29 2024 *)

PARI

a(n) = if (n==1, 1, my(f=factor(n)[,1]~); lcm(vecmin(f), vecmax(f))); \\ Michel Marcus, Mar 15 2018

Formula

a(n) = A097448(A066048(n)). - Amiram Eldar, Mar 16 2025