A216550 Numbers n such that (2^n+1)/3 is prime and can be written in the form a^2 + 3*b^2.

7, 13, 19, 31, 43, 61, 79, 127, 199, 313, 2617, 10501, 12391, 14479, 138937, 141079, 986191

Offset: 1

Author

V. Raman, Sep 08 2012

Keywords

• nonn

Comments

The exponent is congruent to 1 mod 3.

Links

• Samuel S. Wagstaff, Jr. The Cunningham Project

Crossrefs

Cf. A000978.