A109358 Square root of squares of form 2*p + 3, where p is prime.

3, 5, 7, 11, 13, 19, 23, 25, 29, 31, 37, 41, 47, 55, 65, 67, 73, 77, 79, 91, 97, 101, 103, 109, 119, 143, 151, 155, 157, 161, 187, 197, 205, 209, 211, 221, 227, 233, 235, 239, 245, 253, 257, 263, 265, 275, 287, 289, 293, 299, 305, 307, 323, 331, 337, 349, 353

Offset: 1

Author

Giovanni Teofilatto, Aug 22 2005

Keywords

• nonn

Comments

Numbers n such that (n^2-3)/2 is prime. - Robert Israel, Jan 22 2018

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A098828, A109367.

Programs

Maple

select(t -> isprime((t^2-3)/2), [seq(n,n=1..1000,2)]); # Robert Israel, Jan 22 2018

Mathematica

Select[Table[(2Prime[n] + 3)^(1/2), {n, 7000}], IntegerQ] (* Ray Chandler, Aug 25 2005 *)

Formula

a(n) = SQRT(A109367(n)).

Extensions

Extended by Ray Chandler, Aug 25 2005