A200996 - OEIS

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A200996

Least upper limit for numbers u and v such that u*n-1 and v*n+1 are both prime, u and v not necessarily distinct.

5

3, 2, 2, 1, 4, 1, 4, 2, 2, 2, 4, 1, 8, 2, 2, 2, 6, 1, 10, 2, 2, 2, 6, 3, 6, 4, 4, 3, 6, 1, 10, 3, 4, 3, 4, 2, 4, 5, 6, 2, 4, 1, 6, 2, 4, 3, 6, 2, 4, 3, 2, 2, 4, 2, 6, 3, 4, 3, 12, 1, 8, 5, 4, 3, 6, 2, 6, 2, 2, 2, 8, 1, 14, 2, 2, 3, 6, 3, 4, 3, 8, 2, 4, 4, 12

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OFFSET

1,1

COMMENTS

A103689(n) <= a(n) <= A071558(n).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = max {A053989(n), A034693(n)}.

PROG

(Haskell)

a200996 n = max (a053989 n) (a034693 n)

CROSSREFS

Sequence in context: A068448 A054081 A164585 * A154364 A183043 A050604

Adjacent sequences: A200993 A200994 A200995 * A200997 A200998 A200999

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Feb 14 2013

STATUS

approved