exp(−μ·n·HVL) = 2^{−n}: 1/2, 1/4, 1/8 at n=1,2,3; 1/1024 at n=10

Sympy-exact symbolic witness of the multiplicative Beer-Lambert attenuation evaluated at integer multiples of the HVL. Setup: substitute μ · x = μ · n · HVL = n · ln 2 into exp(−μ x), yielding exp(−n ln 2) = 2^{−n}. Pins at n = 1, 2, 3,…