A144938 Squares k such that k - 2 and k + 2 are prime.

9, 81, 225, 441, 1089, 13689, 56169, 74529, 91809, 95481, 149769, 184041, 194481, 199809, 263169, 314721, 328329, 370881, 651249, 804609, 1071225, 1147041, 1238769, 1306449, 1520289, 1535121, 1718721, 2442969, 2595321, 2614689

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Sep 25 2008

Keywords

• nonn
• easy

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000290, A087679.

Programs

Mathematica

lst={};Do[p=n^2;If[PrimeQ[p-2]&&PrimeQ[p+2],AppendTo[lst,p]],{n,1,7!,2}];lst

PARI

forstep(n=3,1e3,6,if(isprime(n^2-2)&&isprime(n^2+2),print1(n^2", "))) \\ Charles R Greathouse IV, Oct 05 2011

Formula

A087679 intersect A000290. - R. J. Mathar, Dec 11 2020