Superposition of a subset of integers

I would do something like this :

n = 5 #number of qubits
N = 2**n #32
sup = [0.]*N
start = 12 #your 13, considering list index starts at 0
norm = N-start #used for normalisation of the vector we'll pass
for i in range(start, N): 
    #creation of the list where the 0s are at indices on the first part you don't want
    sup[i]=np.sqrt(1/norm)

qc = QuantumCircuit(n)
qc.initialize(sup, range(n))
qc.draw()

Tell me if something isn't clear :)