In this paper, we investigate the factor properties and gap sequence of the Tri- bonacci sequence, the fixed point of the substitution σ（a, b, c） = （ab, ac, a）. Let Wp be the p-th occurrence of w and Gp（ω） be ...In this paper, we investigate the factor properties and gap sequence of the Tri- bonacci sequence, the fixed point of the substitution σ（a, b, c） = （ab, ac, a）. Let Wp be the p-th occurrence of w and Gp（ω） be the gap between Wp and Wp＋l. We introduce a notion of kernel for each factor w, and then give the decomposition of the factor w with respect to its kernel. Using the kernel and the decomposition, we prove the main result of this paper： for each factor w, the gap sequence {Gp（ω）}p≥1 is the Tribonacci sequence over the alphabet {G1 （ω）, G2（ω）, G4（ω）}, and the expressions of gaps are determined completely. As an application, for each factor w and p C ∈N, we determine the position of Wp. Finally we introduce a notion of spectrum for studying some typical combinatorial properties, such as power, overlap and separate of factors.展开更多
Each Tribonacci sequence starting with an arbitrary triple of integers is periodic modulo m for any modulus m 〉 1. For a given m, the mapping between the set S of all m^3 triples of initial values and the set of thei...Each Tribonacci sequence starting with an arbitrary triple of integers is periodic modulo m for any modulus m 〉 1. For a given m, the mapping between the set S of all m^3 triples of initial values and the set of their coresponding periods define a partition of the set S. In this paper we shall investigate some basic questions related to these partitions from the point of view of enumerative combinatorics.展开更多
基金supported by grants from the National Science Foundation of China(114310071127122311371210)
文摘In this paper, we investigate the factor properties and gap sequence of the Tri- bonacci sequence, the fixed point of the substitution σ（a, b, c） = （ab, ac, a）. Let Wp be the p-th occurrence of w and Gp（ω） be the gap between Wp and Wp＋l. We introduce a notion of kernel for each factor w, and then give the decomposition of the factor w with respect to its kernel. Using the kernel and the decomposition, we prove the main result of this paper： for each factor w, the gap sequence {Gp（ω）}p≥1 is the Tribonacci sequence over the alphabet {G1 （ω）, G2（ω）, G4（ω）}, and the expressions of gaps are determined completely. As an application, for each factor w and p C ∈N, we determine the position of Wp. Finally we introduce a notion of spectrum for studying some typical combinatorial properties, such as power, overlap and separate of factors.
文摘Each Tribonacci sequence starting with an arbitrary triple of integers is periodic modulo m for any modulus m 〉 1. For a given m, the mapping between the set S of all m^3 triples of initial values and the set of their coresponding periods define a partition of the set S. In this paper we shall investigate some basic questions related to these partitions from the point of view of enumerative combinatorics.
