A139500 Primes of the form x^2 + 20x*y + y^2 for x and y nonnegative.

97, 157, 229, 577, 661, 709, 829, 1453, 1549, 1609, 1621, 1873, 2017, 2137, 2473, 2677, 2689, 2797, 2953, 3001, 3037, 3217, 3301, 3433, 3457, 3613, 3733, 4093, 4261, 4273, 4357, 4513, 4621, 4657, 4801, 4933, 5113, 5281, 5437, 5641, 6229, 6301, 6337

Offset: 1

Author

Artur Jasinski, Apr 24 2008

Keywords

• nonn

Links

• N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Crossrefs

Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491.

Programs

Mathematica

a = {}; w = 20; k = 1; Do[Do[If[PrimeQ[n^2 + w*n*m + k*m^2], AppendTo[a, n^2 + w*n*m + k*m^2]], {n, m, 400}], {m, 1, 400}]; Union[a] (*Artur Jasinski*)
With[{nn=50},Take[Select[Union[Flatten[Table[x^2+20 x y +y^2,{x,0,2nn},{y,0,2nn}]]],PrimeQ],nn]] (* Harvey P. Dale, Nov 02 2022 *)