A023836 - OEIS

%I #13 Nov 08 2017 17:06:27

%S 0,3,4,6,6,8,8,11,11,12,11,14,13,16,13,17,14,18,15,19,20,21,21,23,23,

%T 22,22,24,22,27,22,29,26,28,27,31,29,31,31,31,31,32,32,35,34,35,32,39,

%U 34,37,35,38,37,40,37,41,40,42,40,43,43,44,43,46,43,45,42,46,45,48,43,50,46,48,50,50,50

%N Sum of exponents in prime-power factorization of C(4n,2n-2).

%H Ivan Neretin, <a href="/A023836/b023836.txt">Table of n, a(n) for n = 1..10000</a>

%t Join[{0},Rest[Total[Last[Transpose[FactorInteger[#]]]]&/@(Binomial[ 4#,2#-2]&/@Range[80])]] (* _Harvey P. Dale_, Jun 07 2011 *)

%K nonn

%O 1,2

%A _Clark Kimberling_