A104146 Smallest k>0 such that n*10^k + k is prime.

1, 3, 1, 1, 3, 1, 1, 147, 17, 1, 3, 7, 1, 297, 1

Offset

1,2

Comments

(a(n) mod 10) in {1,3,7,9}.

a(16), if it exists, is greater than 20000. - Ryan Propper, Jul 21 2006

a(16), if it exists, is greater than 42000. - Ryan Propper, Sep 25 2006

Links

Table of n, a(n) for n=1..15.

Crossrefs

a(floor(A030430(n)/10)) = 1.

Sequence in context: A083985 A109848 A371098 * A326405 A193179 A133705

Adjacent sequences: A104143 A104144 A104145 * A104147 A104148 A104149

Keyword

nonn,more

Author

Reinhard Zumkeller, Mar 07 2005

Status

approved