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A049270
Smallest nonnegative value taken on by nx^2 - 11y^2 for an infinite number of integer pairs (x, y).
1
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
1,2
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 *)
CROSSREFS
Sequence in context: A325970 A347781 A088152 * A025269 A265656 A137296
KEYWORD
nonn
STATUS
approved