Белратюк, ЛеонідBedratyuk, L.2019-12-102019-12-102019Bedratyuk L. The double star sequences and the general second zagreb index / L. Bedratyuk // Matematychni Studii. – 2019. – Vol. 51, No. 2. – P. 115–123. L. Bedratyuk. The double star sequences and the general second Zagreb index , Mat. Stud. 51 (2019), 115–123.https://elar.khmnu.edu.ua/handle/123456789/8046For a simple graph we introduce notions of the double star sequence, the double star fre- quently sequence and prove that these sequences are inverses of each other. As a consequence, we express the general second Zagreb index in terms of the double star sequence. Also, we calculate the ordinary generating function and a linear recurrence relation for the sequence of the general second Zagreb indices.engraph theoryZagreb indicesСтаття