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A034923 Numbers n such that 43^n-42 is prime. 0
4, 6, 42, 64, 65, 1017 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Related to hyperperfect numbers of a certain form.

The 1017 term produces a 1662-digit number which is only a probable prime. Any additional terms are greater than 1500.

The next terms are > 3000. - Vincenzo Librandi, Sep 27 2012

LINKS

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

J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3.

MATHEMATICA

Select[Range[1500], PrimeQ[43^# - 42] &] (* Vincenzo Librandi, Sep 27 2012 *)

PROG

(PARI) for(n=2, 1500, if(isprime(43^n-42), print1(n, ", ")))

CROSSREFS

Sequence in context: A175349 A023644 A145387 * A013022 A012908 A077100

Adjacent sequences:  A034920 A034921 A034922 * A034924 A034925 A034926

KEYWORD

nonn,more

AUTHOR

Jud McCranie

EXTENSIONS

a(6) from Rick L. Shepherd, Jun 21 2002

STATUS

approved

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Last modified December 8 11:12 EST 2016. Contains 278939 sequences.