OFFSET

1,1

COMMENTS

Except for 26, all numbers are divisible by 10 and the tens digit is an odd number.

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..1000

EXAMPLE

351650 = 593^2 + 1 (593 is prime) and 351650^2 + 1 is prime, so 351650 is a member of this sequence.

PROG

(Python)

import sympy

from sympy import isprime

{print(n**2+1) for n in range(10**7) if isprime(n) if isprime((n**2+1)**2+1)}

CROSSREFS

KEYWORD

nonn

AUTHOR

Derek Orr, Jan 03 2014

STATUS

approved