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A243702 Nonnegative numbers represented by the indefinite quadratic form x^2+13xy-9y^2. 1
0, 1, 4, 5, 9, 16, 20, 21, 25, 36, 39, 45, 49, 51, 59, 64, 80, 81, 84, 91, 100, 105, 119, 121, 125, 131, 139, 141, 144, 156, 159, 169, 180, 189, 195, 196, 201, 204, 221, 225, 236, 241, 245, 255, 256, 269, 271, 279, 289, 291, 295, 320, 324, 329, 336, 351, 359 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Discriminant 205.

LINKS

Table of n, a(n) for n=1..57.

Will Jagy, C++ program Conway_Positive_All.cc to find all positive numbers represented by an indefinite binary quadratic form

Will Jagy, Sample output from Conway_Positive_All.cc

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

PROG

(C++, Jagy's program, see link)

Conway_Positive_All 1 13 -9 500

CROSSREFS

Primes: A243701.

Sequence in context: A087948 A010437 A020682 * A155565 A278336 A051216

Adjacent sequences:  A243699 A243700 A243701 * A243703 A243704 A243705

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jun 17 2014

STATUS

approved

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Last modified September 25 02:25 EDT 2021. Contains 347651 sequences. (Running on oeis4.)