A177224 a(n) is the least prime of the form ((2n+1)^k - (2n-1)^k)/2.

13, 609554401, 109, 193, 51001, 433, 44937854708156010721, 769

Offset: 1

Author

Alexander Adamchuk, May 05 2010

Keywords

• hard
• nonn

Comments

a(9) = (19^163 - 17^163)/2 is too large to include here.

Corresponding values of k (odd primes) are listed in A122478.

Crossrefs

Cf. A122478, A028491, A121877.

Formula

a(n) = ((2n+1)^A122478(n) - (2n-1)^A122478(n)) / 2.

Extensions

Edited by Max Alekseyev, May 16 2010