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A107607 Numbers n such that prime(n) - n is a perfect power. 3
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified August 6 18:25 EDT 2020. Contains 336256 sequences. (Running on oeis4.)