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A255390 Primes of the form 173^k - 172^k. 0
89269, 184438202074309, 379889466040169687349246148321558634248221737128245658182879616485078366262882828905566134219669 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
a(4) has 1569 digits, a(5) has 2030 digits. - Vincenzo Librandi, Feb 22 2015
The values of k are 3, 7, 43, 701, 907, ... - Jinyuan Wang, May 30 2020
LINKS
Michael P. May, On the Existence and Frequency Distribution of the Shell Primes, arXiv preprint arXiv:1510.01028 [math.CO], 2015.
MATHEMATICA
Select[Table[173^n - 172^n, {n, 1000}], PrimeQ] (* Vincenzo Librandi, Feb 22 2015 *)
PROG
(Magma) [a: n in [0..200] | IsPrime(a) where a is (173^n-172^n)]; // Vincenzo Librandi, Feb 22 2015
(PARI) select(m->ispseudoprime(m), vector(100, k, 173^k-172^k)) \\ Jinyuan Wang, May 30 2020
CROSSREFS
Cf. A254298.
Sequence in context: A237902 A184028 A209896 * A347076 A205290 A205898
KEYWORD
nonn
AUTHOR
Michael P. May, Feb 21 2015
STATUS
approved

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Last modified May 24 04:16 EDT 2024. Contains 372772 sequences. (Running on oeis4.)