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A214714
Least m>0 such that prime(n)-m and n-m are relatively prime.
2
1, 1, 2, 2, 4, 1, 4, 1, 4, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 2, 2, 4, 1, 2, 3, 2, 1, 2, 1, 2, 1, 2, 2, 4, 2, 6, 1, 2, 1, 4, 1, 2, 1, 2, 2, 2, 1, 2, 1, 4, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 1, 4, 1, 2, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 1, 4, 2, 4, 1, 2, 2, 4, 1, 2, 3, 2
OFFSET
1,3
COMMENTS
Does every positive integer occur?
LINKS
EXAMPLE
gcd(16,6) = 2, gcd(15,5) = 5, gcd(14,4) = 2, gcd(13,3) = 1, so a(7) = 4.
MATHEMATICA
Table[m = 1; While[GCD[Prime[n] - m, n - m] != 1, m++]; m, {n, 1, 140}]
CROSSREFS
Cf. A214052.
Sequence in context: A264799 A248503 A359855 * A023137 A327488 A065273
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jul 27 2012
STATUS
approved