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A094599
Numbers n such that the Lebesgue-Nagell equation x^2 + n = y^k, with k > 2, has an integer solution.
3
1, 2, 4, 7, 8, 11, 12, 13, 15, 16, 17, 18, 19, 20, 23, 25, 26, 27, 28, 31, 32, 35, 39, 40, 44, 45, 47, 48, 49, 53, 54, 55, 56, 60, 61, 63, 64, 65, 67, 71, 72, 74, 76, 77, 79, 80, 81, 83, 87, 89, 92, 95, 96, 97, 99, 100
OFFSET
1,2
MATHEMATICA
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]
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
T. D. Noe, May 13 2004
STATUS
approved