%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_