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A062594 Numbers n such that 28^n - 27^n is prime. 0
3, 5, 19, 31, 257, 773 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Terms > 1000 are often only strong pseudoprimes.

a(7) > 10^5. - Robert Price, Sep 04 2012

LINKS

Table of n, a(n) for n=1..6.

PROG

(PARI) is(n)=ispseudoprime(28^n-27^n) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Sequence in context: A215131 A068990 A228471 * A128027 A128066 A273020

Adjacent sequences:  A062591 A062592 A062593 * A062595 A062596 A062597

KEYWORD

nonn,hard

AUTHOR

Mike Oakes, May 18 2001, May 19 2001

STATUS

approved

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Last modified April 8 14:29 EDT 2020. Contains 333314 sequences. (Running on oeis4.)