13/01/04 12:56:44.03
>>62
Io言語
f:=method(n,a:=5 sqrt;2**n-(((1+a)/2)**(n+2)/a)round)
Io> f(3)
==> 3
Io> f(20)
==> 1030865
Io> f(49)
==> 5.629296e+014
Io> f(49)asString(0,0)
==> 562929588410238
13/01/04 12:56:44.03
>>62
Io言語
f:=method(n,a:=5 sqrt;2**n-(((1+a)/2)**(n+2)/a)round)
Io> f(3)
==> 3
Io> f(20)
==> 1030865
Io> f(49)
==> 5.629296e+014
Io> f(49)asString(0,0)
==> 562929588410238