Python,codewars,Twice linear,5672682212c8ecf83e000050
# Twice linear
# https://www.codewars.com/kata/5672682212c8ecf83e000050/train/python
def dbl_linear(n):
# i=0
# j=0
i,j = 0,0 #同时定义多个变量的方式
sequence = [1]
while len(sequence) <= n:
sequence.append(min(2*sequence[i]+1,3*sequence[j]+1))
if sequence[-1] == 2*sequence[i]+1:
i+=1
if sequence[-1] == 3*sequence[j]+1:
j+=1
return sequence[-1]