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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Does every positive integer occur?

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..1000

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: A171942 A264799 A248503 * A023137 A327488 A065273

Adjacent sequences:  A214711 A214712 A214713 * A214715 A214716 A214717

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Jul 27 2012

STATUS

approved

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Last modified July 27 09:47 EDT 2021. Contains 346304 sequences. (Running on oeis4.)