Structures of non-GDJ golay sequences

The existence of 1024 quaternary length 16 Golay sequences not within Davis and Jedwab's construction was verified previously by exhaustive search. This paper discusses the structures of these non-GDJ Golay sequences. Unlike GDJ Golay sequences which are in specific second order cosets of the generalized first order Reed Muller code, these sequences are distributed in 16 cosets containing third order Boolean function terms, 64 sequences from each coset. They are shown to be the result of concatenating or interleaving pairing length 8 GDJ Golay sequences from different Golay cosets