A174623 (2^p+1)^2 where p is prime.

25, 81, 1089, 16641, 4198401, 67125249, 17180131329, 274878955521, 70368760954881, 288230377225453569, 4611686022722355201, 18889465931753458761729, 4835703278462914745335809, 77371252455353859367239681, 19807040628566365873362698241

Offset: 1

Author

Vincenzo Librandi, Apr 11 2010

Keywords

• nonn

Examples

			For p=2, (2^2+1)^2=25;
for p=3, (2^3+1)^2=81;
for p=5, (2^5+1)^2=1089.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200

Programs

Magma

[(2^p+1)^2: p in [0..1000] |IsPrime(p)]

Maple

A174623:=n->(2^ithprime(n)+1)^2: seq(A174623(n), n=1..20); # Wesley Ivan Hurt, Apr 18 2017

Mathematica

Table[(2^Prime[n] + 1)^2, {n, 30}] (* Vincenzo Librandi, Apr 29 2014 *)

Formula

a(n) = (A098640(n))^2. - R. J. Mathar, Jul 06 2010

Extensions

Definition clarified by Jon E. Schoenfield, Jun 18 2010