A242625 Primes p such that p + prime(p) is a square.

5, 241, 503, 3299, 4861, 9749, 10501, 11633, 13799, 14057, 23003, 40493, 56569, 74323, 90023, 90641, 185177, 224633, 307187, 367097, 648887, 732761, 766679, 954221, 997103, 1004567, 1070423, 1095491, 1100311, 1252997, 1284083, 1434757, 1483397, 1695139, 1716521, 1720151, 2115823, 2176817

Offset

1,1

Links

Zak Seidov, Table of n, a(n) for n = 1..100

Example

p = 5, q = prime(5) = 11, p + q = 16 = 4^2.
p = 241, q = prime(241) = 1523, p + q = 1764 = 42^2.

Mathematica

Select[Prime[Range[200000]], IntegerQ[Sqrt[#+Prime[#]]]&] (* Harvey P. Dale, Apr 15 2019 *)

Prog

(PARI) s=[]; forprime(p=2, 3000000, if(issquare(p+prime(p)), s=concat(s, p))); s \\ Colin Barker, May 19 2014

Crossrefs

Cf. A073136.

Sequence in context: A174767 A230885 A142732 * A085115 A317165 A327582

Adjacent sequences: A242622 A242623 A242624 * A242626 A242627 A242628

Keyword

nonn

Author

Zak Seidov, May 19 2014

Status

approved