The Cayley isomorphism property for groups of order 8p

Abstract

For every prime p > 3 we prove that Q x Z_p is a DCI-group. Using the same method we reprove the fact that Z_2^3 x Z_p is a CI-group for every prime p > 3, which was obtained in E. Dobson, P. Spiga, CI-groups with respect to ternary relational structures: new examples, Ars Math. Contemp. 6 (2012), 351-364. This result completes the description of CI-groups of order 8p.