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Sum of exponents in prime-power factorization of n-th prime - 1.
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%I #24 Apr 16 2024 02:40:20

%S 0,1,2,2,2,3,4,3,2,3,3,4,4,3,2,3,2,4,3,3,5,3,2,4,6,4,3,2,5,5,4,3,4,3,

%T 3,4,4,5,2,3,2,5,3,7,4,4,4,3,2,4,4,3,6,4,8,2,3,5,4,5,3,3,4,3,5,3,4,6,

%U 2,4,6,2,3,4,5,2,3,5,6,5,3,5,3,7,3,3,7,5,4,4,2,2,6,4,3,2,3,5,4

%N Sum of exponents in prime-power factorization of n-th prime - 1.

%H Amiram Eldar, <a href="/A023508/b023508.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A001222(A006093(n)). - _R. J. Mathar_, Feb 06 2019

%t Array[Plus@@Last/@FactorInteger[Prime[ # ]-1]&,6! ] (* _Vladimir Joseph Stephan Orlovsky_, Feb 28 2010 *)

%t PrimeOmega[Prime[Range[100]] - 1] (* _Amiram Eldar_, Apr 16 2024 *)

%o (PARI) a(n) = bigomega(prime(n)-1); \\ _Amiram Eldar_, Apr 16 2024

%Y Cf. A001222, A008334, A006093, A210936.

%K nonn,easy

%O 1,3

%A _Clark Kimberling_