ملخص
Let PCn be the semigroup of all decreasing and order-preserving partial transformations of a finite chain. It is shown that |PCn| = rn, where rn is the large (or double) Schröder number. Moreover, the total number of idempotents of PCn is shown to be (3n +1)/2.
اللغة الأصلية | English |
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دورية | Journal of Integer Sequences |
مستوى الصوت | 7 |
رقم الإصدار | 3 |
حالة النشر | Published - 2004 |
منشور خارجيًا | نعم |
ASJC Scopus subject areas
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