高校数学の質問スレ Part438

f[n_]:=f[n]=If[n==1,0,(1/Sum[Binomial[n,k]/3^(n-1),{k,1,n-1}])*(1+Sum[Binomial[n,k]/3^(n-1) f[k],{k,1,n-1}])];
Table[N[f[k],10],{k,{50,100,150,200,250,300,350,400,450,500}}]

{2.125639851 10^8 , 1.355203941 10^17 , 8.641071598 10^25 , 5.509733036 10^34 , 3.513124244 10^43 ,
2.240043551 10^52 , 1.428299930 10^61 , 9.107147438 10^69 , 5.806913012 10^78 , 3.702612586 10^87 }