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 A023848 #15 Jun 14 2025 04:19:04
%S A023848 1,5,4,8,6,10,11,13,11,15,13,16,16,18,18,20,18,20,18,25,21,23,22,27,
%T A023848 24,30,28,28,28,31,32,33,29,33,32,36,32,36,37,39,35,40,32,37,38,38,39,
%U A023848 40,40,43,41,48,44,47,47,49,45,50,47,53,50,53,50,52,50,54,50,52,53,54,57,58,55,59,57,62
%N A023848 Sum of exponents in prime-power factorization of binomial(5n, 2n-1).
%H A023848 Ivan Neretin, <a href="/A023848/b023848.txt">Table of n, a(n) for n = 1..10000</a>
%F A023848 a(n) = A023847(n) - A001222(3*n+1) + A001222(2*n). - _Amiram Eldar_, Jun 14 2025
%t A023848 Table[PrimeOmega[Binomial[5 n, 2 n - 1]], {n, 77}] (* _Ivan Neretin_, Nov 09 2017 *)
%o A023848 (PARI) a(n) = bigomega(binomial(5*n,2*n-1)); \\ _Amiram Eldar_, Jun 14 2025
%Y A023848 Cf. A001222, A023837, A023839, A023840, A023841, A023842, A023843, A023844, A023845, A023846, A023847, A023849, A023850, A023851.
%K A023848 nonn
%O A023848 1,2
%A A023848 _Clark Kimberling_