A049270 Smallest nonnegative value taken on by nx^2 - 11y^2 for an infinite number of integer pairs (x, y).
1, 2, 1, 1, 1, 6, 7, 8, 9, 10, 0, 1, 2, 3, 1, 4, 6, 7, 8, 4, 10, 11, 1, 13, 1, 5, 1, 13, 2, 19, 1, 13, 22, 5, 19, 9, 1, 3, 7, 29, 6, 31, 32, 0, 1, 2, 1, 4, 5, 6, 7, 8, 1, 10, 11, 5, 13, 14, 1, 1, 2, 2, 7, 5, 6, 22, 1, 17, 1, 5, 1, 13, 13, 7, 1, 13, 33, 34, 7, 16, 25, 22, 8, 13, 10, 3, 19, 44, 1
Offset: 1
Keywords
Programs
-
Mathematica
f[n_, z_] := FindInstance[x > 0 && y > 0 && n*x^2 - 11*y^2 == z, {x, y}, Integers, 1]; a[n_] := For[z = 0, True, z = z + GCD[n, 11], fz = f[n, z]; If[fz =!= {}, Print["a(", n, ") = ", z, " {x,y} = ", {x, y} /. fz[[1]]]; Return[z]]]; Array[a, 89] (* Jean-François Alcover, Oct 09 2016 *)