a(n) is the number of representative four-color bracelets (necklaces with turning over allowed) with n beads, for n >= 4.
A214309
a(n) is the number of representative four-color bracelets (necklaces with turning over allowed) with n beads, for n >= 4.
Terms
- a(0) =3a(1) =6a(2) =26a(3) =93a(4) =424a(5) =1180a(6) =4844a(7) =16165a(8) =66953a(9) =216804a(10) =852822a(11) =2949804a(12) =12119134a(13) =40886724a(14) =160826008a(15) =572457489a(16) =2331396595a(17) =8104270828a(18) =32043699894a(19) =115995102806a(20) =471268872328
External references
- oeis: A214309