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 A243655 Positive numbers that are primitively represented by the indefinite quadratic form x^2 - 3y^2 of discriminant 12. 13
 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 June 15 12:29 EDT 2021. Contains 345048 sequences. (Running on oeis4.)