根据f(n)=n2+1(n∈N,n≥1),且f1(n)=f(n),f2(n)=f(f1(n))........fk+1(n)=f(fk(n)).(k∈N,k≥1)可知:f(8)=82+1=65=6+5=11。又f1(8)=f(8)=11,f2(8)=f(f1(8))=f(11)112+1=121+1=122=1+2+2=5,f3(8)=f(f2(8))=f(5)=52+1=26=2+6=8, f4(8)=f(f3(8))=f(8)=11,f5(8)=f(f4(8))=f(11)=5.f6(8)=f(f5(8))=f(5)=8,f7(8)=f(f6(8))=f(8)=11,f8(8)=f(f7(
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