>>134
M=Table[If[n==m,1-(2^m-2)/3^(m-1),Binomial[m,n]/3^(m-1)],{m,1,11},{n,1,11}];
u=Table[Boole[i==11],{i,1,11}];
v=Table[Boole[i== 1],{i,1,11}];
p=Differences@Table[u.MatrixPower[M,i].v,{i,0,20}];

max=Max[p]
12597340638043496499971512842764330462294598371/515377520732011331036461129765621272702107522001

Position[p,max]
11