A309243 Completely multiplicative with a(p) = p * a(p-1) for any prime number p.

1, 2, 6, 4, 20, 12, 84, 8, 36, 40, 440, 24, 312, 168, 120, 16, 272, 72, 1368, 80, 504, 880, 20240, 48, 400, 624, 216, 336, 9744, 240, 7440, 32, 2640, 544, 1680, 144, 5328, 2736, 1872, 160, 6560, 1008, 43344, 1760, 720, 40480, 1902560, 96, 7056, 800, 1632, 1248

Offset: 1

Author

Rémy Sigrist, Jul 17 2019

Keywords

• nonn
• mult

Comments

All terms are distinct and belong to A064522.

Examples

			a(2) = 2 * a(1) = 2.
a(5) = 5 * a(4) = 5 * a(2)^2 = 5 * 2^2 = 20.
		

Links

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

Crossrefs

Cf. A000010, A006530, A053585, A064415, A064522.

Programs

PARI

a(n) = my (f=factor(n), p=f[,1]~, e=f[,2]~); prod (i=1, #p, (p[i] * a(p[i] - 1))^e[i])

Formula

a(n) >= n with equality iff n is a power of 2.

a(n) is a multiple of n.

a(n) is a multiple of A000010(n).

A006530(a(n)) = A006530(n).

A053585(a(n)) = A053585(n).

Apparently, A007814(a(n)) = A064415(n).