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A136167
a(n) = the number of divisors of n that are each not coprime to any adjacent (previous or following) divisor of n.
6
1, 0, 0, 1, 0, 1, 0, 2, 1, 1, 0, 2, 0, 1, 1, 3, 0, 3, 0, 2, 1, 1, 0, 4, 1, 1, 2, 2, 0, 3, 0, 4, 1, 1, 1, 5, 0, 1, 1, 3, 0, 3, 0, 2, 2, 1, 0, 6, 1, 3, 1, 2, 0, 5, 1, 3, 1, 1, 0, 6, 0, 1, 2, 5, 1, 3, 0, 2, 1, 3, 0, 6, 0, 1, 3, 2, 1, 3, 0, 5, 3, 1, 0, 5, 1, 1, 1, 4, 0, 5, 1, 2, 1, 1, 1, 8, 0, 3, 2, 5, 0, 3, 0, 4, 3
OFFSET
1,8
EXAMPLE
The divisors of 28 are 1,2,4,7,14,28. Among adjacent pairs of divisors, 1 and 2 are coprime and 4 and 7 are coprime. Therefore there are a(28) =2 divisors that are each not next to any divisor they are coprime to. (These two divisors are 14 and 28.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Dec 17 2007
EXTENSIONS
More terms from Diana L. Mecum, Jul 13 2008
STATUS
approved