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A139829 Primes of the form 4x^2+4xy+11y^2. 1
11, 19, 59, 131, 139, 179, 211, 251, 331, 379, 419, 491, 499, 571, 619, 659, 691, 739, 811, 859, 971, 1019, 1051, 1091, 1171, 1259, 1291, 1451, 1459, 1499, 1531, 1571, 1579, 1619, 1699, 1811, 1931, 1979, 2011, 2099, 2131, 2179, 2251, 2339, 2371 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Discriminant=-160. See A139827 for more information.
Also, primes of form u^2+10v^2 with odd v, while A107145 has even v. One can transform its form as (2x+y)^2+10y^2 (where y can only be odd) and the latter is x^2+10(2y)^2. This sequence has primes {11,19} mod 20 while the second has {1,9} mod 20 and together they are the primes x^2+10y^2 (A033201) which are {1,9,11,20} mod 20. [From Tito Piezas III, Jan 01 2009]
LINKS
Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi]
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
FORMULA
The primes are congruent to {11, 19} (mod 40).
MATHEMATICA
QuadPrimes2[4, -4, 11, 10000] (* see A106856 *)
PROG
(Magma) [ p: p in PrimesUpTo(3000) | p mod 40 in {11, 19}]; // Vincenzo Librandi, Jul 29 2012
CROSSREFS
Sequence in context: A189888 A227930 A224383 * A138355 A265802 A178385
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, May 02 2008
STATUS
approved

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Last modified March 19 02:55 EDT 2024. Contains 370952 sequences. (Running on oeis4.)