Number of series-reduced free pure symmetric identity multifunctions (with empty expressions allowed) with one atom and n positions.

A317880

Number of series-reduced free pure symmetric identity multifunctions (with empty expressions allowed) with one atom and n positions.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =8a(7) =16a(8) =33a(9) =70a(10) =152a(11) =333a(12) =735a(13) =1635a(14) =3668a(15) =8285a(16) =18823a(17) =42970a(18) =98535a(19) =226870a(20) =524290a(21) =1215641a(22) =2827203a(23) =6593432a(24) =15416197a(25) =36129894a(26) =84860282a(27) =199719932a(28) =470930802a(29) =1112388190

External references