A139505 Primes of the form x^2 + 25x*y + y^2 for x and y nonnegative.

151, 163, 307, 397, 409, 541, 547, 601, 673, 811, 823, 859, 967, 997, 1153, 1231, 1237, 1327, 1567, 1669, 1741, 1879, 2083, 2143, 2281, 2293, 2557, 2677, 2707, 2833, 2971, 3037, 3259, 3313, 3433, 3877, 4003, 4129, 4153, 4603, 4639, 4861, 4957, 5101, 5227

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..5000

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

Mathematica

a = {}; w = 25; 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=80}, Select[Union[#[[1]]^2+25#[[1]]#[[2]]+#[[2]]^2&/@Tuples[ Range[ 0, nn], 2]], PrimeQ[#]&&#<nn^2&]] (* Harvey P. Dale, Feb 10 2020 *)

Crossrefs

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

Sequence in context: A250312 A180554 A243531 * A095745 A112796 A186459

Adjacent sequences: A139502 A139503 A139504 * A139506 A139507 A139508

Keyword

nonn

Author

Artur Jasinski, Apr 24 2008

Status

approved