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 A243655 Positive numbers that are primitively represented by the indefinite quadratic form x^2 - 3y^2 of discriminant 12. 7
 1, 6, 13, 22, 33, 37, 46, 61, 69, 73, 78, 94, 97, 109, 118, 121, 141, 142, 157, 166, 169, 177, 181, 193, 213, 214, 222, 229, 241, 249, 253, 262, 277, 286, 313, 321, 334, 337, 349, 358, 366, 373, 382, 393, 397, 409, 421, 429, 433, 438, 454, 457, 478, 481 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS x^2+2xy-2y^2 is an equivalent form. LINKS Will Jagy, Sample output from Conway_Positive_All.cc Will Jagy, Sample output from Conway_Positive_Prim.cc N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) MATHEMATICA Reap[For[n = 1, n < 500, n++, r = Reduce[x^2 - 3 y^2 == n, {x, y}, Integers]; If[r =!= False, If[AnyTrue[{x, y} /. {ToRules[r /. C[1] -> 0]}, CoprimeQ @@ # &], Print[n]; Sow[n]]]]][[2, 1]] (* Jean-François Alcover, Oct 31 2016 *) CROSSREFS Cf. A084916 (all numbers represented), A068228. Sequence in context: A056115 A173358 A101247 * A072212 A028872 A049718 Adjacent sequences:  A243652 A243653 A243654 * A243656 A243657 A243658 KEYWORD nonn AUTHOR N. J. A. Sloane, Jun 11 2014 STATUS approved

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Last modified December 18 18:07 EST 2018. Contains 318243 sequences. (Running on oeis4.)