A326778 a(n) is the least k such that A213636(k) = n.

1, 2, 48, 24, 180, 300, 17640, 20160, 22680, 25200, 166320, 83160, 4324320, 9369360, 2162160, 7207200, 98017920, 49008960, 2793510720, 2095133040, 1396755360, 698377680, 1847208963600, 1927522396800, 2007835830000, 2088149263200, 2168462696400, 2248776129600

Offset: 1

Author

Rémy Sigrist, Jul 29 2019

Keywords

• nonn

Crossrefs

Cf. A003418, A151800, A213636.

Programs

PARI

A213636(n) = for (d=2, oo, if (n%d, return (n%d)))
a(n) = my (l=lcm([1..n])); forstep (x=l, oo, l, if (A213636(x)==n, return (x/l)))

Formula

a(n) is a multiple if A003418(n).

a(n) mod p = n where p is the least prime number > n.