A180949 Prime numbers P such that 10^(n+d+1) + P*10^n + 1 is prime for n=1 to 5 with d = number of digits of P.

223283, 248903, 924773, 1469627, 2121767, 2428241, 2429411, 2614043, 2885453, 3444893, 3512849, 3564461, 4316141, 4438067, 4605977, 4980161, 5267519, 6248057, 6961673, 7519607, 8517563, 9716789, 9846443, 12383099, 13127507

Offset

1,1

Comments

For P = 6961673,9846443,17990729,28587371 Q is prime for n=1 to 6

For P = 5267519,27060587 Q is prime for n=1 to 7

Links

Table of n, a(n) for n=1..25.

Example

5267519
1052675191
10526751901
105267519001
1052675190001
10526751900001
105267519000001
1052675190000001
are all prime numbers

Crossrefs

Sequence in context: A258907 A253739 A274809 * A165411 A235909 A233966

Adjacent sequences: A180946 A180947 A180948 * A180950 A180951 A180952

Keyword

nonn,base

Author

Pierre CAMI, Sep 27 2010

Status

approved