Python中的幸运数

 
∑ Digits(N2) = N

Number, N = 9           (1)
Square of Number, N2 = N x N = 9 x 9 = 81
Sum of the Digits of N2 = 8 + 1 = 9             (2)
From Equation (1) and (2), we have:
Sum of Digits of N2 = Number N
i.e., 9 = 9
Thus, Number 9 is a Neon Number.

Number, N = 0             (1)
Square of Number, N2 = N x N = 0 x 0 = 0
Sum of the Digits of N2 = 0             (2)
From Equation (1) and (2), we have:
Sum of Digits of N2 = Number N
i.e., 0 = 0Thus, Number 0 is a Neon Number.

Number, N = 12                (1)
Square of Number, N2 = N x N = 12 x 12 = 144
Sum of the Digits of N2 = 1 + 4 + 4 = 9                (2)
From Equation (1) and (2), we have:
Sum of Digits of N2 is not equal to Number N
i.e., 9 != 12
Thus, Number 12 is NOT a Neon Number.

Number, N = 30                  (1)
Square of Number, N2 = N x N = 30 x 30 = 900
Sum of the Digits of N2 = 9 + 0 + 0 = 9                  (2)
From Equation (1) and (2), we have:
Sum of Digits of N2 is not equal to Number N
i.e., 9 != 30
Thus, Number 30 is NOT a Neon Number.