2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69703This article gives a brief introduction to the On-Line Encyclopedia of Integer Sequences (or OEIS). The OEIS is a database of nearly 90,000 sequences of integers, arranged lexicographically. The entry for a sequence lists the initial terms (50 to 100, if available), a description, formulae, programs to generate the sequence, references, links to relevant web pages, and other information.9 pages, 1 figCombinatoricsNumber Theory05-00, 11-00, 40-00text