ClearAll[Combination,Permutation]
Combination[n_,k_]:=Binomial[n,k]
Permutation[n_,k_]:=Binomial[n,k]k!

TableForm[Array[Permutation,{12,12}],TableHeadings->{Range[12],Range[12]}]
TableForm[Array[Combination,{6,6},{{10,60},{10,60}}],TableHeadings->{Range[10,60,10],Range[10,60,10]}]
{Row[{#,"P",#-2},"  "],N@Permutation[#,#-2]}&/@{5,1000,5000,10000,15000}//Grid
{Row[{#,"C",#/2},"  "],N@Combination[#,#/2]}&/@Range[100,1000,100]//Grid