On the Non-existence of certain classes of perfect p-ary sequences and   perfect almost p-ary sequences
  We obtain new non-existence results of perfect p-ary sequences with period n (called type $[p, n]$). The first case is a class with type [p\equiv5\pmod 8,p^aqn']. The second case contains five types [p\equiv3\pmod 4,p^aq^ln'] for certain $p, q$ and $l$. Moreover, we also have similar non-existence results for perfect almost p-ary sequences. 
Chang Lv
cs.IT math.IT math.NT