A088659 a(n) = n*(p-1) where p is the largest prime factor of n.

2, 6, 4, 20, 12, 42, 8, 18, 40, 110, 24, 156, 84, 60, 16, 272, 36, 342, 80, 126, 220, 506, 48, 100, 312, 54, 168, 812, 120, 930, 32, 330, 544, 210, 72, 1332, 684, 468, 160, 1640, 252, 1806, 440, 180, 1012, 2162, 96, 294, 200, 816, 624, 2756, 108, 550, 336, 1026

Offset: 2

Author

Benoit Cloitre, Nov 21 2003

Keywords

• nonn

Comments

It is conjectured that sequence gives period length of the periodic sequence {A088957(k) mod n}_{k>n}.

The records of this sequence are given by A036689 (product of a prime and the previous number). - Michel Marcus, May 19 2015

Links

• Ivan Neretin, Table of n, a(n) for n = 2..1000

Programs

Maple

seq(n*(max(numtheory:-factorset(n))-1), n=2..100); # Robert Israel, May 19 2015

Mathematica

Table[n*(FactorInteger[n][[-1, 1]] - 1), {n, 2, 57}] (* Ivan Neretin, May 19 2015 *)

PARI

a(n)=n*(component(factor(n),1)-1)

Formula

For p the k-th prime, a(p) = A036689(k). - Michel Marcus, May 19 2015

a(n) = n*A070777(n). - Michel Marcus, May 19 2015