A106887 - OEIS

A106887

Primes of the form 2x^2-xy+5y^2, with x and y nonnegative.

2, 5, 11, 47, 71, 137, 149, 167, 239, 281, 317, 353, 383, 401, 449, 461, 509, 557, 593, 683, 761, 773, 827, 839, 941, 947, 977, 983, 1097, 1103, 1229, 1259, 1307, 1319, 1409, 1493, 1523, 1553, 1721, 1787, 1931, 1997, 2039, 2069, 2087, 2111, 2153

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Discriminant=-39.

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)

MATHEMATICA

QuadPrimes2[2, -1, 5, 10000] (* see A106856 *)

CROSSREFS

Sequence in context: A088149 A153989 A160859 * A236044 A285809 A089609

Adjacent sequences: A106884 A106885 A106886 * A106888 A106889 A106890

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 09 2005

STATUS

approved