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.

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

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