Number of unlabeled mappings (or mapping patterns) from n points to themselves; number of unlabeled endofunctions.

A001372

Number of unlabeled mappings (or mapping patterns) from n points to themselves; number of unlabeled endofunctions.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =7a(4) =19a(5) =47a(6) =130a(7) =343a(8) =951a(9) =2615a(10) =7318a(11) =20491a(12) =57903a(13) =163898a(14) =466199a(15) =1328993a(16) =3799624a(17) =10884049a(18) =31241170a(19) =89814958a(20) =258604642a(21) =745568756a(22) =2152118306a(23) =6218869389a(24) =17988233052a(25) =52078309200a(26) =150899223268a(27) =437571896993

External references