OFFSET
1,1
COMMENTS
All terms are odd, and if n is even, then 5^n - 4^n is divisible by 3. [Vincenzo Librandi, Nov 25 2010]
The next term (a(5)) has 156 digits. - Harvey P. Dale, May 14 2022
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..9
EXAMPLE
5^3 - 4^3 = 125 - 64 = 61.
MAPLE
select(isprime, [seq(5^n - 4^n, n=0..200)]); # Muniru A Asiru, Mar 04 2018
MATHEMATICA
lst={}; Do[p=5^n-4^n; If[PrimeQ[p], AppendTo[lst, p]], {n, 6!}]; lst
Select[Table[5^n-4^n, {n, 300}], PrimeQ] (* Harvey P. Dale, May 14 2022 *)
PROG
(GAP) Filtered(List([1..200], n->5^n - 4^n), IsPrime); # Muniru A Asiru, Mar 04 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Nov 10 2008
STATUS
approved