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A049248 Smallest nonnegative value taken on by 9x^2 - ny^2 for an infinite number of integer pairs (x, y). 0
0, 1, 6, 0, 1, 3, 2, 1, 0, 9, 9, 9, 9, 1, 9, 0, 1, 9, 5, 1, 9, 9, 1, 9, 0, 1, 9, 8, 1, 6, 2, 4, 3, 2, 1, 0, 9, 9, 9, 9, 1, 9, 9, 9, 9, 2, 1, 9, 0, 1, 9, 9, 1, 9, 5, 1, 9, 9, 9, 9, 5, 1, 9, 0, 1, 9, 9, 1, 3, 9, 1, 9, 8, 1, 6, 5, 1, 3, 2, 1, 0, 9, 9, 9, 9, 9, 9, 9, 1, 9, 9, 4, 9, 2, 1, 9, 8, 1, 9, 0, 1, 9, 2, 1, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..105.

MATHEMATICA

p = 9; 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 == 97, z = 8; fz = $Aborted, n == 103, z = 2; 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, 105}] (* Jean-Fran├žois Alcover, Oct 11 2016 *)

CROSSREFS

Sequence in context: A063085 A020796 A011253 * A178601 A094691 A095715

Adjacent sequences:  A049245 A049246 A049247 * A049249 A049250 A049251

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified June 4 17:50 EDT 2020. Contains 334828 sequences. (Running on oeis4.)