Thread: A new sequence View Single Post
2020-12-01, 21:23   #3
sweety439

"99(4^34019)99 palind"
Nov 2016
(P^81993)SZ base 36

72×73 Posts

Quote:
 Originally Posted by Jens K Andersen A132469(n) = (2^(5n)-1)/31 = (32^n-1)/31 = base 32 generalized repunits.
There are no primes in this sequence, since 32^n-1 = (2^n-1) * (16^n+8^n+4^n+2^n+1), and since the two factors are both >31 for n>5 ((32^n-1)/31 is not prime for all 1<=n<=5), thus the factorization is not trivial.