OFFSET
1,2
COMMENTS
a(35) >= 9. See link to factordb.com - Hugo Pfoertner, Aug 07 2019
LINKS
Chris Caldwell, The First 1000 Primes.
Dario Alejandro Alpern, Factorization using the Elliptic Curve Method
factordb.com, Status of prime(n)^prime(n)+1.
EXAMPLE
If p=29 then (29^29 + 1) contains 7 distinct prime factors.
MATHEMATICA
f[n_] := Length@ FactorInteger[Prime[n]^Prime[n] + 1]; Array[f, 20] (* Robert G. Wilson v, Apr 06 2006 *)
PROG
(PARI) { for(n=1, 20, p = prime(n); d = factor(p^p+1); dec=matsize(d); print1(dec[1], ", "); ); } \\ R. J. Mathar, Mar 29 2006
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Parthasarathy Nambi, Mar 14 2006
EXTENSIONS
8 more terms from R. J. Mathar, Mar 29 2006
a(19)-a(25) from Robert G. Wilson v, Apr 06 2006
a(26)-a(32) from Sean A. Irvine, Oct 20 2011
a(33)-a(34) from Hugo Pfoertner, Aug 07 2019
a(28) corrected by Sean A. Irvine, Aug 04 2023
STATUS
approved