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 A049250 Smallest nonnegative value taken on by 11x^2 - ny^2 for an infinite number of integer pairs (x, y). 0

%I

%S 2,1,8,7,6,3,1,3,2,1,0,11,11,2,11,11,3,9,1,11,11,11,7,3,11,2,8,4,3,5,

%T 11,3,11,10,1,8,7,6,5,4,3,2,1,0,11,11,11,11,2,1,3,11,6,5,11,8,11,2,8,

%U 11,11,3,9,11,11,11,7,3,11,11,11,11,11,1,11,4,11,2,1,11,2,11,1,11,11,6

%N Smallest nonnegative value taken on by 11x^2 - ny^2 for an infinite number of integer pairs (x, y).

%t p = 11; f[n_, z_] := FindInstance[x > 0 && y > 0 && p*x^2 - n*y^2 == z, {x, y}, Integers, 1]; a[n_] := For[z = 0, z <= p, z = z + GCD[n, p], Which[n == 64, z = 11; fz = \$Aborted, True, fz = TimeConstrained[f[n, z], 300]]; fz = If[fz === \$Aborted, {{x -> Null, y -> Null}}, fz]; If[fz =!= {}, Print["a(", n, ") = ", z, " {x, y} = ", {x, y} /. fz[[1]]]; Return[z]]]; Table[a[n], {n, 1, 86}] (* _Jean-François Alcover_, Oct 11 2016 *)

%K nonn

%O 1,1

%A _David W. Wilson_, Dec 11 1999

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Last modified September 25 16:13 EDT 2020. Contains 337344 sequences. (Running on oeis4.)