A023824 - OEIS

%I #12 Nov 02 2017 17:53:09

%S 0,2,4,5,5,6,6,8,8,8,11,13,11,11,11,12,12,13,13,15,14,17,17,19,16,16,

%T 20,19,18,18,18,23,19,18,21,22,20,22,23,24,23,24,26,28,29,27,27,30,27,

%U 28,28,29,27,31,30,32,32,31,35,36,32,31,33,34,31,32,33,34,32,34,34,38,33,35,38,37,38,36,33

%N Sum of exponents in prime-power factorization of C(3n,n+2).

%H Ivan Neretin, <a href="/A023824/b023824.txt">Table of n, a(n) for n = 1..10000</a>

%e For n=4, C(12,6) = 924 = 2^2*3*7*11, so a(4) = @+1+1+1 = 5.

%t Table[Total[FactorInteger[Binomial[3n,n+2]][[All,2]]],{n,2,80}] (* _Harvey P. Dale_, Dec 24 2016 *)

%K nonn

%O 1,2

%A _Clark Kimberling_

%E a(1)=0 added by _Ivan Neretin_, Nov 02 2017