Number of permutation groups of degree n; also number of conjugacy classes of subgroups of symmetric group S_n; also number of molecular species of degree n.

A000638

Number of permutation groups of degree n; also number of conjugacy classes of subgroups of symmetric group S_n; also number of molecular species of degree n.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =11a(5) =19a(6) =56a(7) =96a(8) =296a(9) =554a(10) =1593a(11) =3094a(12) =10723a(13) =20832a(14) =75154a(15) =159129a(16) =686165a(17) =1466358a(18) =7274651

External references