This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A023508 #24 Apr 16 2024 02:40:20 %S A023508 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 A023508 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 A023508 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 A023508 Sum of exponents in prime-power factorization of n-th prime - 1. %H A023508 Amiram Eldar, <a href="/A023508/b023508.txt">Table of n, a(n) for n = 1..10000</a> %F A023508 a(n) = A001222(A006093(n)). - _R. J. Mathar_, Feb 06 2019 %t A023508 Array[Plus@@Last/@FactorInteger[Prime[ # ]-1]&,6! ] (* _Vladimir Joseph Stephan Orlovsky_, Feb 28 2010 *) %t A023508 PrimeOmega[Prime[Range[100]] - 1] (* _Amiram Eldar_, Apr 16 2024 *) %o A023508 (PARI) a(n) = bigomega(prime(n)-1); \\ _Amiram Eldar_, Apr 16 2024 %Y A023508 Cf. A001222, A008334, A006093, A210936. %K A023508 nonn,easy %O A023508 1,3 %A A023508 _Clark Kimberling_