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A243174 Nonnegative integers of the form x^2 + 5*x*y - 5*y^2 (discriminant 45). 4
0, 1, 4, 9, 16, 19, 25, 31, 36, 45, 49, 55, 61, 64, 76, 79, 81, 99, 100, 109, 121, 124, 139, 144, 145, 151, 169, 171, 180, 181, 196, 199, 205, 211, 220, 225, 229, 241, 244, 256, 261, 271, 279, 289, 295, 304, 316, 319, 324, 331, 349, 355, 361, 369, 379, 396, 400, 405, 409, 421, 436, 439, 441, 445, 451, 475, 484, 495, 496, 499, 505, 529, 531, 541, 549 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Also numbers representable as x^2 + 7*x*y + y^2 with 0 <= x <= y. - Gheorghe Coserea, Jul 29 2018

Also numbers of the form x^2 - x*y - 11*y^2 with 0 <= x <= y (or x^2 + x*y - 11*y^2 with x, y nonnegative). - Jianing Song, Jul 31 2018

LINKS

Gheorghe Coserea, Table of n, a(n) for n = 1..100001

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

CROSSREFS

Cf. A028957, A031363.

Primes: A033212.

Sequence in context: A035234 A313325 A313326 * A313327 A313328 A313329

Adjacent sequences:  A243171 A243172 A243173 * A243175 A243176 A243177

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jun 01 2014

STATUS

approved

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Last modified July 28 22:55 EDT 2021. Contains 346340 sequences. (Running on oeis4.)