For any transcendental entire function f(z)=∑n≥0anzn, define .
M(r,f):=∣z∣=rmax∣f(z)∣,μ(r,f):=n≥0max∣an∣rn.
Following [Er1961], define
β(f):=r→∞liminfM(r,f)μ(r,f).
We define C51=B to be the supremum of β(f) over all transcendental entire functions f.