Pseudo Sylow Numbers

One part of Sylow’s famous theorem in group theory states that the number of Sylow p-subgroups of a finite group is always congruent to 1 modulo p. Conversely, Marshall Hall has shown that not every positive integer n≡1 (modp) occurs as the number of Sylow p-subgroups of some finite group. While Hall’s proof relies on deep knowledge of modular representation theory, we show by elementary means that no finite group has exactly 35 Sylow 17-subgroups.