We completely classify the Lee-extremal self-dual codes over 2+u2 of lengths 23 and 24 with a nontrivial automorphism of odd order. In particular, we show that there is no Lee-extremal self-dual code of length 23 with a nontrivial automorphism of odd order, there are 41 inequivalent Lee-extremal Type I codes of length 24 with a nontrivial automorphism of odd order and there exists one Lee-extremal Type II code of length 24 with a nontrivial automorphism of odd order, up to equivalence. Moreover, Lee-extremal Type II codes of length 24 have an automorphism of order 3.
Bibliographical noteFunding Information:
The author was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) ( NRF-2013R1A1A2063240 ).
All Science Journal Classification (ASJC) codes
- Theoretical Computer Science
- Algebra and Number Theory
- Applied Mathematics