%I #3 Mar 30 2012 17:22:33
%S 1,2,4,7,8,11,12,13,15,16,17,18,19,20,23,25,26,27,28,31,32,35,39,40,
%T 44,45,47,48,49,53,54,55,56,60,61,63,64,65,67,71,72,74,76,77,79,80,81,
%U 83,87,89,92,95,96,97,99,100
%N Numbers n such that the Lebesgue-Nagell equation x^2 + n = y^k, with k > 2, has an integer solution.
%t lst=Table[cnt=0; Do[x=Sqrt[y^k-n]; If[IntegerQ[x], cnt++ ], {k, 3, 20}, {y, 600}]; cnt, {n, 2, 100}]; Complement[Range[100], Flatten[Position[lst, 0]]+1]
%Y Cf. A094596, A094597, A094598.
%K hard,nonn
%O 1,2
%A _T. D. Noe_, May 13 2004
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