Untitled

R.<x> = QQ[]

def defInt(F, a, b):
    FInt = F.integral()
    return FInt.subs(x=b) - FInt.subs(x=a)

eVal = 2.0 #=P(0)+P(1)
F = x
for j in range(2, 150):
    F = x*F.subs(x=1/2) - defInt(F, 0, x) + 2*defInt(F, 0, x/2) + 2*defInt(F, (1-x)/2, 1/2)
    eVal += float(2*F(1/2))
    
print (eVal)