A074954 Least perfect power b^e such that b^e-n is also a perfect power, or 0 if no such perfect power exists.

9, 27, 4, 8, 9, 0, 8, 9, 25, 2197, 27, 16, 49, 0, 16, 25, 25, 27, 27, 36, 25, 49, 27, 25, 125, 27, 36, 32, 225, 6889, 32, 36, 49, 0, 36, 100, 64, 1369, 64, 49, 49, 0, 484, 125, 49, 289, 128, 49, 81, 0, 100, 196, 729, 81, 64, 64, 121, 0, 900, 64, 125, 0, 64, 100, 81, 0, 1156

Offset

1,1

Comments

a(A074981) = 0.

Links

Table of n, a(n) for n=1..67.

Eric Weisstein's World of Mathematics, Perfect Power.

Example

a(30) = 6889: 30 = 83^2 - 19^3.

Crossrefs

Cf. A001597.

Sequence in context: A056399 A256927 A135864 * A103952 A103955 A359531

Adjacent sequences: A074951 A074952 A074953 * A074955 A074956 A074957

Keyword

nonn

Author

Reinhard Zumkeller, Oct 10 2002

Status

approved