Number of free pure symmetric identity multifunctions with one atom and n positions.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =2a(5) =1a(6) =5a(7) =5a(8) =15a(9) =23a(10) =54a(11) =98a(12) =212a(13) =420a(14) =886a(15) =1822a(16) =3838a(17) =8046a(18) =17029a(19) =36097a(20) =76889a(21) =164245a(22) =351971a(23) =756341a(24) =1629389a(25) =3518643a(26) =7614717a(27) =16512962a(28) =35875986a(29) =78082171