OFFSET
1,2
COMMENTS
All terms correspond to verified primes, that is, not merely probable primes. - Robert Price, Jan 16 2015
a(16) > 3*10^5. - Robert Price, Jan 16 2015
MATHEMATICA
Select[Range[0, 2000], PrimeQ[4*5^#+1]&]
PROG
(PARI) is(n)=ispseudoprime(4*5^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
José María Grau Ribas, Jan 14 2012
EXTENSIONS
a(8)-a(15) from Robert Price, Jan 16 2015
a(16)-a(19) from Ryan Propper, Dec 20 2023
a(20) from Ryan Propper, Jan 04 2024
STATUS
approved