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A062593 Numbers n such that 27^n - 26^n is prime. 1
2, 13, 157, 43117 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Terms > 1000 are often only strong pseudoprimes.

a(5) > 10^5. - Robert Price, Aug 12 2012.

LINKS

Table of n, a(n) for n=1..4.

PROG

(PARI) is(n)=ispseudoprime(27^n-26^n) \\ Charles R Greathouse IV, Jun 12 2017

CROSSREFS

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

Sequence in context: A054382 A297408 A316701 * A291140 A192563 A014507

Adjacent sequences:  A062590 A062591 A062592 * A062594 A062595 A062596

KEYWORD

nonn,hard

AUTHOR

Mike Oakes, May 18 2001, May 19 2001

EXTENSIONS

a(4) from Robert Price, Aug 12 2012

STATUS

approved

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Last modified April 10 02:18 EDT 2020. Contains 333392 sequences. (Running on oeis4.)