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 A023842 #10 Jun 14 2025 04:18:32
%S A023842 0,3,3,6,6,8,8,11,10,12,9,13,13,15,11,17,16,16,15,18,16,22,22,23,22,
%T A023842 23,20,22,22,24,22,27,22,25,25,26,24,29,24,29,30,28,27,31,31,33,32,39,
%U A023842 35,37,34,39,36,41,38,39,37,37,34,37,39,43,38,41,40,40,39,44,40,42,42,46,47,49,46,46,47
%N A023842 Sum of exponents in prime-power factorization of C(5n,n-5).
%H A023842 Ivan Neretin, <a href="/A023842/b023842.txt">Table of n, a(n) for n = 5..10000</a>
%F A023842 From _Amiram Eldar_, Jun 14 2025: (Start)
%F A023842 a(n) = A001222(A004347(n)).
%F A023842 a(n) = A023841(n) - A001222(4*n+5) + A001222(n-4). (End)
%t A023842 Table[PrimeOmega[Binomial[5 n, n - 5]], {n, 5, 81}] (* _Ivan Neretin_, Nov 08 2017 *)
%o A023842 (PARI) a(n) = bigomega(binomial(5*n,n-5)); \\ _Amiram Eldar_, Jun 14 2025
%Y A023842 Cf. A001222, A004347, A023837, A023838, A023839, A023840, A023841, A023843, A023844, A023845, A023846, A023847, A023848, A023849, A023850, A023851.
%K A023842 nonn
%O A023842 5,2
%A A023842 _Clark Kimberling_
%E A023842 Offset corrected to 5 by _Ivan Neretin_, Nov 08 2017