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A139502 Primes of the form x^2 + 22x*y + y^2 for x and y nonnegative. 5
241, 409, 601, 769, 1009, 1129, 1201, 1249, 1321, 1489, 1609, 1801, 2089, 2161, 2281, 2521, 2689, 3001, 3049, 3121, 3169, 3361, 3529, 3769, 3889, 4129, 4201, 4441, 4561, 4729, 4801, 4969, 5209, 5281, 5449, 5521, 5569, 5641, 5689, 5881, 6121, 6361, 6481 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also primes of the form x^2 + 120y^2. - T. D. Noe, Apr 29 2008

Also primes of the form x^2+240y^2. See A140633. - T. D. Noe, May 19 2008

In base 12, the sequence is 181, 2X1, 421, 541, 701, 7X1, 841, 881, 921, X41, E21, 1061, 1261, 1301, 13X1, 1561, 1681, 18X1, 1921, 1981, 1X01, 1E41, 2061, 2221, 2301, 2481, 2521, 26X1, 2781, 28X1, 2941, 2X61, 3021, 3081, 31X1, 3241, 3281, 3321, 3361, 34X1, 3661, 3821, 3901, where X is 10 and E is 11. Moreover, the discriminant is 340. - Walter Kehowski, Jun 01 2008

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

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

FORMULA

The primes are congruent to {1, 49} (mod 120). - T. D. Noe, Apr 29 2008

MATHEMATICA

QuadPrimes2[1, 0, 120, 10000] (* see A106856 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(7000) | p mod 120 in {1, 49}]; // Vincenzo Librandi, Jul 28 2012

CROSSREFS

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

Cf. A139643.

Sequence in context: A153423 A050968 A142918 * A140629 A325088 A321582

Adjacent sequences:  A139499 A139500 A139501 * A139503 A139504 A139505

KEYWORD

nonn,easy

AUTHOR

Artur Jasinski, Apr 24 2008

STATUS

approved

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Last modified July 22 10:03 EDT 2019. Contains 325219 sequences. (Running on oeis4.)