EntityQ1138140· pop 5· linked from 7 articlessquarefree wordSign in to savea sequence of symbols that does not contain any repeated contiguous subsequenceConnectionsalphabetEntityInternational Standard Book NumberEntitydigital object identifierEntityInternational Standard Serial NumberEntitycombinatoricsEntityOCLC, Inc.EntitybibcodeEntityQ118398EntityCambridge University PressEntitystringEntityautomata theoryEntityOn-Line Encyclopedia of Integer SequencesEntityrecurrence relationEntityQ22908627EntitySpringer Science+Business MediaEntityAmerican Mathematical SocietyEntityAxel ThueEntityHandle SystemEntitymorphismEntitybrute-force searchEntityCategoriesCombinatorics on wordsFormal languages