A186303 a(n) = ( A007522(n)+1 )/2.

4, 12, 16, 24, 36, 40, 52, 64, 76, 84, 96, 100, 112, 120, 132, 136, 156, 180, 184, 192, 216, 220, 232, 240, 244, 252, 300, 304, 316, 324, 360, 364, 372, 376, 412, 420, 432, 444, 456, 460, 484, 492, 496, 516, 520, 532, 544

Offset: 1

Author

Marco Matosic, Feb 17 2011

Keywords

• nonn
• easy

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007522, A186302.

Programs

Mathematica

(#+1)/2&/@Select[8*Range[0,300]+7,PrimeQ] (* Harvey P. Dale, Jul 14 2011 *)

PARI

is(n)=n%4==0&&isprime(2*n-1) \\ Charles R Greathouse IV, Jan 22 2013

Formula

a(n) = A186302(n)+1.