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A070956 Number of pairs (x,y) such that n = gcd(x,y) + lcm(x,y). 0
0, 1, 1, 2, 1, 3, 2, 3, 2, 3, 2, 5, 2, 4, 4, 5, 1, 5, 2, 5, 5, 5, 2, 7, 3, 4, 4, 6, 2, 8, 4, 6, 4, 4, 5, 9, 2, 4, 5, 8, 2, 9, 4, 7, 7, 5, 2, 10, 4, 6, 4, 7, 2, 8, 5, 9, 5, 5, 2, 12, 4, 6, 8, 8, 4, 10, 4, 6, 5, 10, 4, 12, 2, 4, 8, 7, 6, 10, 4, 11, 6, 4, 2, 13, 6, 7, 5, 10, 2, 13, 8, 8, 7, 5, 5, 13, 2, 7, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n)=1 for n prime = 2,3,5,17,...;

a(n)=2 if n = 4 or 9, or n is in A067466(k).

LINKS

Table of n, a(n) for n=1..99.

CROSSREFS

Sequence in context: A305030 A110917 A329340 * A237127 A262746 A007828

Adjacent sequences:  A070953 A070954 A070955 * A070957 A070958 A070959

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, May 16 2002

STATUS

approved

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Last modified November 13 15:41 EST 2019. Contains 329106 sequences. (Running on oeis4.)