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A242664 Nonnegative integers of the form x^2+6xy-y^2. 1
0, 1, 4, 6, 9, 10, 15, 16, 24, 25, 26, 31, 36, 39, 40, 41, 49, 54, 60, 64, 65, 71, 74, 79, 81, 86, 89, 90, 96, 100, 104, 106, 111, 121, 124, 129, 134, 135, 144, 150, 151, 156, 159, 160, 164, 166, 169, 185, 186, 191, 196, 199, 201, 214, 215, 216, 225, 234, 239, 240, 241, 246, 249, 250, 256, 260, 265, 271, 279, 281, 284, 289, 294, 296 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Discriminant 40.

LINKS

Table of n, a(n) for n=1..74.

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

MATHEMATICA

Reap[For[n = 0, n <= 300, n++, If[Reduce[ x^2 + 6*x*y - 1*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]]

CROSSREFS

Primes in this sequence = A141180.

Sequence in context: A005659 A010462 A028957 * A084662 A137167 A181564

Adjacent sequences:  A242661 A242662 A242663 * A242665 A242666 A242667

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, May 31 2014

STATUS

approved

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Last modified July 25 19:05 EDT 2021. Contains 346291 sequences. (Running on oeis4.)