A few days ago I asked a question (http://mathoverflow.net/questions/158302) about a finite group of order $p(p^2+1)/2$ and I get many useful information about it. Thanks for the nice and very helpful answers. Now I have a question: is it possible we conclude that any group of order $(p^2+1)/2$, where $p>5$ is a prime, has an abelian and normal Sylow subgroup?