Constructing R-sequencings and terraces for groups of even order
نویسنده
چکیده
The problem of finding R-sequencings for abelian groups of even orders has been reduced to that of finding R∗sequencings for abelian groups of odd orders except in the case when the Sylow 2-subgroup is a non-cyclic non-elementary-abelian group of order 8. We partially address this exception, including all instances when the group has order 8t for t congruent to 1, 2, 3 or 4 (mod 7). As much is known about which odd-order abelian groups are R∗-sequenceable, we have constructions of R-sequencings for many new families of abelian groups. The construction is generalisable in several directions, leading to a wide array of new Rsequenceable and terraceable non-abelian groups of even order.
منابع مشابه
R-sequencings and strong half-cycles from narcissistic terraces
We construct narcissistic terraces for cyclic groups that have various properties which enable the construction of R-sequencings and strong halfcycles for many non-cyclic abelian groups. Among other results, we show: that an abelian group which is isomorphic to a direct product of cyclic factors such that the number of factors of order congruent to 3 (mod 4) of order at most 79 is at least as l...
متن کاملAll groups of odd order have starter-translate 2-sequencings
Bailey defined 2-sequencings (terraces) of groups. She conjectured that all finite groups except elementary Abelian 2-groups (other than the cyclic group Z2) have 2-sequencings and proved that the direct product of a 2-sequenceable group and a cyclic group of odd order is 2-sequenceable. It is shown here that all groups of odd order have a special type of 2-sequencing called a starter-translate...
متن کاملA note on terraces for abelian groups
We adapt a construction for R-sequencings to give new terraces for abelian groups. This enables the construction of terraces for all groups of the form Z2×Zt where k ≥ 4 and t > 5 is odd. We also present an extendable terrace for Z2 × Z5. When combined with known results this shows that any abelian counterexample to Bailey’s Conjecture (which asserts that all groups except the elementary abelia...
متن کاملSequenceable Groups and Related Topics
In 1980, about 20 years after sequenceable groups were introduced by Gordon to construct row-complete latin squares, Keedwell published a survey of all the available results concerning sequencings. This was updated (jointly with Dénes) in 1991 and a short overview, including results about complete mappings and Rsequencings, was given in the CRC Handbook of Combinatorial Designs in 1995. In Sect...
متن کاملSome Cyclic Solutions to the Three Table Oberwolfach Problem
We use graceful labellings of paths to give a new way of constructing terraces for cyclic groups. These terraces are then used to find cyclic solutions to the three table Oberwolfach problem, OP(r, r, s), where two of the tables have equal size. In particular we show that, for every odd r ≥ 3 and even r with 4 ≤ r ≤ 16, there is a number Nr such that there is a cyclic solution to OP(r, r, s) wh...
متن کامل