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

Author

Reinhard Zumkeller, Feb 14 2013

Keywords

• nonn

Comments

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

Links

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

Programs

Haskell

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

Formula

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