A091176 Numbers n such that prime(n) is of the form 2*k^2 - 1.

4, 7, 11, 20, 25, 31, 46, 53, 68, 87, 106, 118, 152, 163, 190, 204, 247, 344, 377, 418, 436, 474, 492, 516, 558, 580, 647, 669, 713, 816, 894, 975, 1003, 1028, 1179, 1300, 1392, 1526, 1561, 1695, 1768, 1917, 1952, 2069, 2177, 2343, 2601, 2643, 2769, 2812

Offset: 1

Author

Ray Chandler, Dec 25 2003

Keywords

• nonn

Comments

A066436 indexed by A000040.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A066049, A066436, A090697, A110558.

Programs

Mathematica

Flatten[Position[Prime[Range[3000]],?(IntegerQ[Surd[(#+1)/2,2]]&)]] (* _Harvey P. Dale, Jan 23 2013 *)

Formula

A000040(n) = A066436(n).