Linear codes over finite chain rings.
We address three questions posed by K. Bibak (2020), and generalize some results of K. Bibak, D. N. Lehmer and K. G. Ramanathan on solutions of linear congruences . In particular, we obtain explicit expressions for the number of solutions, where ’s are squares modulo . In addition, we obtain expressions for the number of solutions with order restrictions or with strict order restrictions in some special cases. In these results, the expressions for the number of solutions involve Ramanujan...
Let , where and , and let be a sequence of integers given by the linear recurrence for . We show that there are a prime number and integers such that no element of the sequence defined by the above linear recurrence is divisible by . Furthermore, for any nonnegative integer there is a prime number and integers such that every element of the sequence defined as above modulo belongs to the set .