from sympy import *
init_printing()
A, l = symbols('A λ')
array = []
size = 100
for i in range(1, size+1):
array.append([0]*size)
j = (3*i+1)>>1 if i%2==1 else i>>1
if(j>size): j=i;
array[i-1][j-1] = 1
for i in range(1, size+1):
array[i-1][i-1] += -l;
A = Matrix(array).transpose()
A
factors = A.LUdecompositionFF()
L = factors[0]
U = factors[1]
U
import matplotlib.pyplot as plt
[3*x+2 for x in range(0,12)]
[2*x+1 for x in range(0,12)]