A023827 - OEIS

%I #8 Nov 02 2017 18:44:11

%S 0,3,3,6,4,7,8,10,9,11,8,11,10,15,14,16,13,16,14,18,15,17,17,21,20,21,

%T 19,20,18,22,21,26,21,26,24,27,23,26,28,28,28,30,26,30,27,29,29,33,30,

%U 33,30,33,30,33,31,33,31,33,32,36,35,39,39,42,37,40,38,41,40,42,40,44,41,45,44,46,44,46

%N Sum of exponents in prime-power factorization of C(4n,n-1).

%H Ivan Neretin, <a href="/A023827/b023827.txt">Table of n, a(n) for n = 1..10000</a>

%t Join[{0},Table[Total[Transpose[FactorInteger[Binomial[4n,n-1]]] [[2]]],{n,2,80}]] (* _Harvey P. Dale_, Jun 13 2013 *)

%K nonn

%O 1,2

%A _Clark Kimberling_