Abstract: | The circulant Gn(a1, ⋖, ak), where 0 < a1 < ··· < ak < (n + 1)/2, is defined as the vertex-transitive graph that has vertices i ± a1, ···, i ± ak(mod n) adjacent to each vertex i. In this work we show that the connected circulants of degree at least three contain all even cycles. In addition, we prove that the connected circulants of girth three contain cycles of all lengths. © 1997 John Wiley & Sons, Inc. J Graph Theory 26: 17–25, 1997 |