A212332 - OEIS

A212332

The difference between the largest and smallest prime factor of n as n runs through the numbers with at least two distinct prime factors.

1, 3, 1, 5, 2, 1, 3, 4, 9, 1, 11, 5, 3, 8, 15, 2, 1, 17, 10, 3, 5, 9, 2, 21, 1, 3, 14, 11, 1, 6, 5, 16, 27, 3, 29, 4, 8, 9, 15, 20, 5, 1, 35, 2, 17, 4, 11, 3, 39, 5, 12, 41, 26, 9, 3, 6, 21, 28, 45, 14, 1, 5, 8, 3, 15, 11, 4, 51, 1, 9, 34, 5, 17, 18, 27, 10

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OFFSET

1,2

COMMENTS

a(n) = A100576(n) if A168638(n) contains only two prime distinct divisors.

Nonzero entries of A046665 in the order of appearance. R. J. Mathar, Aug 07 2012

LINKS

Michel Lagneau, Table of n, a(n) for n = 1..10000

EXAMPLE

a(13) = 3 because A168638(13) = 30 = 2*3*5 and 5-2 = 3.

MAPLE

for n from 2 to 200 do