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A068957 Number of prime divisors of n^n - (n-1)^(n-1), counted with multiplicity. 2

%I

%S 1,1,1,2,2,1,4,6,3,1,3,2,4,3,2,1,2,3,4,2,2,3,3,4,9,4,2,2,5,4,6,3,6,4,

%T 4,2,6,7,6,4,3,4,8,6,2,7,4,7,12,6,4,5,5,7,9,5,5,6,2,5,10,4,6,5,5,3,9,

%U 4,4,2,3,4,9,4,6,4,5,7,9,13,8,4,2,5,7

%N Number of prime divisors of n^n - (n-1)^(n-1), counted with multiplicity.

%F a(n) = A001222(A007781(n)).

%e A007781(14) = 10809131718965763 = 3 * 61^2 * 968299894201, therefore a(14) = 4.

%t Table[ Apply[ Plus, Transpose[ FactorInteger[n^n - (n - 1)^(n - 1)]] [[ -1]]], {n, 2, 52}]

%Y Cf. A001222, A007781, A068956.

%K nonn

%O 2,4

%A _Reinhard Zumkeller_, Mar 11 2002

%E Edited and extended by _Robert G. Wilson v_, Mar 15 2002

%E a(53)-a(86) from _Amiram Eldar_, Feb 06 2020

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Last modified May 16 00:49 EDT 2021. Contains 343937 sequences. (Running on oeis4.)