A107608 - OEIS

A107608

Perfect powers which have the form prime(n) - n for some n.

1, 1, 25, 32, 125, 128, 441, 529, 729, 961, 1089, 1369, 2025, 2809, 3375, 4489, 4900, 4913, 9216, 10201, 10404, 12167, 16384, 17576, 18225, 20736, 27889, 31684, 34596, 35344, 38416, 38809, 39601, 40804, 46656, 47961, 60516, 61009, 63504, 65025

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OFFSET

1,3

COMMENTS

Corresponding n's in A107607.

LINKS

Table of n, a(n) for n=1..40.

FORMULA

a(n) = prime(A107607(n)) - A107607(n).

MATHEMATICA

f[n_] := Prime[n] - n; Select[f /@ Range[10^4], ! GCD @@ Last /@ FactorInteger[ # ] == 1 &] (* Ray Chandler, May 21 2005 *)

CROSSREFS

Cf. A001597 (perfect powers), A107605, A107606, A107607 (associated n).

Sequence in context: A225418 A035140 A050694 * A219951 A209333 A131610

Adjacent sequences: A107605 A107606 A107607 * A107609 A107610 A107611

KEYWORD

nonn

AUTHOR

Zak Seidov, May 17 2005

EXTENSIONS

Extended by Ray Chandler, May 21 2005

STATUS

approved