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A062623 Numbers k such that 57^k - 56^k is prime. 0
2, 19, 769, 773, 4507, 26183 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Terms greater than 1000 often correspond only to strong pseudoprimes. [Clarified by M. F. Hasler, Sep 15 2013]

a(7) > 10^5. - Robert Price, Dec 06 2012

LINKS

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

PROG

(PARI) is(n)=ispseudoprime(57^n-56^n) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

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

Sequence in context: A300995 A086976 A118189 * A155956 A013047 A012951

Adjacent sequences:  A062620 A062621 A062622 * A062624 A062625 A062626

KEYWORD

nonn,hard

AUTHOR

Mike Oakes, May 18 2001, May 19 2001

EXTENSIONS

a(6) from Robert Price, Dec 06 2012

STATUS

approved

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Last modified July 30 12:39 EDT 2021. Contains 346359 sequences. (Running on oeis4.)