A094599 Numbers n such that the Lebesgue-Nagell equation x^2 + n = y^k, with k > 2, has an integer solution.

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

Links

Table of n, a(n) for n=1..56.

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

Cf. A094596, A094597, A094598.

Sequence in context: A045601 A167051 A151661 * A050082 A209864 A182654

Adjacent sequences: A094596 A094597 A094598 * A094600 A094601 A094602

Keyword

hard,nonn

Author

T. D. Noe, May 13 2004

Status

approved