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 A139506 Primes of the form x^2 + 26x*y + y^2 for x and y nonnegative. 3
 193, 337, 457, 673, 1009, 1033, 1129, 1201, 1297, 1801, 1873, 2017, 2137, 2377, 2473, 2521, 2689, 2713, 2857, 3049, 3217, 3313, 3361, 3529, 3697, 3889, 4057, 4153, 4201, 4561, 4657, 4729, 4993, 5209, 5233, 5569, 5737, 5881, 6073, 6217, 6337, 6553, 6577 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also primes of the form x^2 + 168y^2. - T. D. Noe, Apr 29 2008 In base 12, the sequence is 141, 241, 321, 481, 701, 721, 7X1, 841, 901, 1061, 1101, 1201, 12X1, 1461, 1521, 1561, 1681, 16X1, 17X1, 1921, 1X41, 1E01, 1E41, 2061, 2181, 2301, 2421, 24X1, 2521, 2781, 2841, 28X1, 2X81, 3021, 3041, 3281, 33X1, 34X1, 3621, 3721, 3801, 3961, 3981, where X is 10 and E is 11. Moreover, the discriminant is 480. - Walter Kehowski, Jun 01 2008 LINKS N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) FORMULA The primes are congruent to {1, 25, 121} (mod 168). - T. D. Noe, Apr 29 2008 MATHEMATICA a = {}; w = 26; 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*) CROSSREFS Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491. Cf. A139643. Sequence in context: A014755 A238667 A216451 * A147171 A146824 A256348 Adjacent sequences:  A139503 A139504 A139505 * A139507 A139508 A139509 KEYWORD nonn AUTHOR Artur Jasinski, Apr 24 2008 STATUS approved

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Last modified July 23 11:44 EDT 2019. Contains 325254 sequences. (Running on oeis4.)