a(1)=1,a(n+1)=n*a(n)/(n*a(n)+n+2) https://www.wolframalpha.com/input?i=a%281%29%3D1%2Ca%28n%2B1%29%3Dn*a%28n%29%2F%28n*a%28n%29%2Bn%2B2%29&lang=ja 再帰方程式の解 a(n) = 1/n^2 Table[1/n2,{n,2,4}] https://www.wolframalpha.com/input?i=Table%5B1%2Fn2%2C%7Bn%2C2%2C4%7D%5D&lang=ja 結果 n | 2 | 3 | 4 1/n^2 | 1/4 | 1/9 | 1/16
a(1)=1,a(n+1)=n*a(n)/(n*a(n)+n+2)
https://www.wolframalpha.com/input?i=a%281%29%3D1%2Ca%28n%2B1%29%3Dn*a%28n%29%2F%28n*a%28n%29%2Bn%2B2%29&lang=ja
再帰方程式の解 a(n) = 1/n^2
Table[1/n2,{n,2,4}]
https://www.wolframalpha.com/input?i=Table%5B1%2Fn2%2C%7Bn%2C2%2C4%7D%5D&lang=ja
結果
n | 2 | 3 | 4
1/n^2 | 1/4 | 1/9 | 1/16