%I #4 Sep 21 2013 12:51:18
%S 4,0,8,0,4,12,0,0,18,14,0,0,10,44,10,0,0,0,50,74,4
%N Triangle T(n,k) (n >= 2, 1 <= k <= n-1) read by rows, where T(n,k) is the number of words of length n in the free group on two generators that require exactly k multiplications for their formation.
%e T(4,2)=4 because we can generate each of aaaa,abab,baba,bbbb with just two multiplications: e.g. ab=a*b, abab=ab*ab.
%Y Cf. A076262.
%K more,nonn,tabl
%O 2,1
%A _Colin Mallows_, Oct 03 2002