The given bound confirms the bounds for n=1 (3) and for n=2 (7) given by Soifer in [S] but improves the bound for n=3 (13 instead of 14).
Resulting upper bounds for n from 1 to 3
The given bound confirms the bounds for n=1 (3) and for n=2 (7) given by Soifer in [S] but improves the bound for n=3 (13 instead of 14).