%I #19 Jul 04 2024 03:36:51
%S 1,2,3,4,4,4,7,8,6,4,8,6,5,7,7,7,10,4,11,10,8,6,13,13,11,9,13,10,15,4,
%T 13,12,13,10,18,11,8,10,16,9,16,6,15,18,9,5,19,20,14,15,17,8,16,12,18,
%U 10,10,5,26,8,10,14,20,19,17,9,17,12,19,7,29,15,8,11,20,13,21,8
%N Number of prime factors of n^n - 1, counted with multiplicity.
%H Amiram Eldar, <a href="/A309941/b309941.txt">Table of n, a(n) for n = 2..138</a> (terms 2..126 from Chai Wah Wu)
%H factordb, <a href="http://factordb.com/index.php?query=n%5En-1&use=n&perpage=20&format=1&sent=1&PR=1&PRP=1&C=1&CF=1&U=1&FF=1&VP=1&EV=1&OD=1&VC=1&n=80">Factors of n^n-1</a>.
%e a(3) = 2: 3^3 - 1 = 26 = 2 * 13.
%e a(5) = 4: 5^5 - 1 = 3124 = 2^2 * 11 * 71.
%t a[n_] := PrimeOmega[n^n - 1]; Array[a, 45, 2] (* _Amiram Eldar_, Jul 04 2024 *)
%o (PARI) for(k=2, 50, print1(bigomega(k^k-1),", "))
%Y Cf. A006486, A048861, A085723, A116895, A125135, A334167, A344870.
%K nonn,hard
%O 2,2
%A _Hugo Pfoertner_, Aug 24 2019