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 A023843 #10 Jun 14 2025 04:18:36
%S A023843 2,5,4,7,7,10,8,11,9,12,12,15,15,15,14,17,15,18,15,21,19,20,18,22,19,
%T A023843 24,24,25,25,27,24,26,25,24,24,28,25,29,27,32,27,33,27,30,34,33,31,33,
%U A023843 32,35,34,40,37,40,38,41,37,42,39,46,42,42,38,40,39,42,38,42,42,43,44,47,44,46,45,48,49
%N A023843 Sum of exponents in prime-power factorization of C(5n,n+1).
%H A023843 Ivan Neretin, <a href="/A023843/b023843.txt">Table of n, a(n) for n = 1..10000</a>
%F A023843 a(n) = A023837(n) + A001222(4*n) - A001222(n+1). - _Amiram Eldar_, Jun 14 2025
%t A023843 Table[PrimeOmega[Binomial[5 n, n + 1]], {n, 77}] (* _Ivan Neretin_, Nov 08 2017 *)
%o A023843 (PARI) a(n) = bigomega(binomial(5*n,n+1)); \\ _Amiram Eldar_, Jun 14 2025
%Y A023843 Cf. A001222, A023837, A023839, A023840, A023841, A023842, A023844, A023845, A023846, A023847, A023848, A023849, A023850, A023851.
%K A023843 nonn
%O A023843 1,1
%A A023843 _Clark Kimberling_