f2=Function[{l,k}, Module[{n=Length@l,m}, m=SparseArray[{{i_,j_}/;i==1||i==j+1->1},{n,n}]; NestList[m.#&,l,k]]]; Table[Last/@f2[{1,1}~Join~Table[0,{n-2}],15+n][[-18;;]],{n,2,10}]//TableForm Table[Last/@f2[{1,2}~Join~Table[0,{n-2}],15+n][[-18;;]],{n,2,10}]//TableForm