Number of reversible string structures with n beads using exactly five different colors.

A056329

Number of reversible string structures with n beads using exactly five different colors.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =9a(6) =76a(7) =542a(8) =3523a(9) =21393a(10) =123680a(11) =690550a(12) =3756151a(13) =20042589a(14) =105394296a(15) =548123982a(16) =2826435403a(17) =14479204833a(18) =73794961960a(19) =374603884910

External references