OFFSET
1,1
COMMENTS
Related to hyperperfect numbers of a certain form.
LINKS
J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3.
MATHEMATICA
Select[Range[2000], PrimeQ[47^# - 46] &] (* Vincenzo Librandi, Sep 26 2012 *)
PROG
(PARI) is(n)=ispseudoprime(47^n-46) \\ Charles R Greathouse IV, Jun 13 2017
(Python)
from sympy import isprime
def afind(limit, startat=1):
pow47 = 47**startat
for k in range(startat, limit+1):
if isprime(pow47 - 46): print(k, end=", ")
pow47 *= 47
afind(900) # Michael S. Branicky, May 11 2021
CROSSREFS
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(6) from Vincenzo Librandi, Sep 26 2012
a(7) from Michael S. Branicky, May 11 2021
STATUS
approved