In the previous paper, it was shown that the graph U. ÷ 1 obtained from the wheel W n ÷ 1 by deleting a spoke is uniquely determined by its chromatic polynomial if n >i 3 is odd. In this paper, we show that the result is also true for even n >~ 4 except when n = 6 in which case, the graph W given in the paper is the only graph having the same chromatic polynomial as that of U 7. The relevant to...

The spectrum of a finite group is the set its element orders. We prove that if $$m>5$$ then $$L_{2^m}(2)\times L_{2^m}(2)\times L_{2^m}(2)$$ uniquely determined by in class groups.