A107607 Numbers n such that prime(n) - n is a perfect power.

1, 2, 12, 15, 38, 39, 100, 118, 152, 190, 212, 258, 352, 462, 542, 690, 741, 746, 1285, 1396, 1417, 1632, 2119, 2243, 2318, 2603, 3370, 3777, 4073, 4155, 4485, 4522, 4600, 4719, 5317, 5446, 6697, 6748, 6985, 7144, 7520, 7595, 9492, 9551, 12010, 12985

Offset

1,2

Links

Table of n, a(n) for n=1..46.

Example

Prime(12) - 12 = 37 - 12 = 25 = 5^2.

Mathematica

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

Prog

(PARI) isA107607(n)=(ispower(prime(n)-n) > 1) || (prime(n)-n == 1) \\ Michael B. Porter, Sep 28 2009

Crossrefs

Cf. A001597 (perfect powers), A107605, A107606, A107608 (associated prime(n)-n).

Sequence in context: A118516 A077103 A036499 * A102975 A120300 A089021

Adjacent sequences: A107604 A107605 A107606 * A107608 A107609 A107610

Keyword

nonn

Author

Zak Seidov, May 17 2005

Extensions

Extended by Ray Chandler, May 21 2005

Status

approved