1,8,18,32, () solve the numbers in brackets What's the next number

1,8,18,32, () solve the numbers in brackets What's the next number

Add the number of digits to every two numbers
For example, if 1 + 8 = 9, then 1 + 8 + 9 = 18
Similarly, if 8 + 18 = 26 and the single digit is 6, then 8 + 18 + 6 = 32
Therefore, 18 + 32 = 50, the number of single digits is 0, and the number of brackets = 18 + 32 + 0 = 50