Number of free pure symmetric multifunctions with one atom, n positions, and no empty or unitary parts (subexpressions of the form x[] or x[y]).

A303027

Number of free pure symmetric multifunctions with one atom, n positions, and no empty or unitary parts (subexpressions of the form x[] or x[y]).

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =3a(7) =5a(8) =7a(9) =15a(10) =28a(11) =47a(12) =90a(13) =175a(14) =319a(15) =607a(16) =1181a(17) =2251a(18) =4325a(19) =8449a(20) =16425a(21) =31992a(22) =62823a(23) =123521a(24) =243047a(25) =480316a(26) =951290a(27) =1886293a(28) =3749341a(29) =7467815

External references