Number of 6-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209487
Number of 6-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
Terms
- a(0) =11a(1) =136a(2) =731a(3) =2606a(4) =7179a(5) =16660a(6) =34233a(7) =64220a(8) =112263a(9) =185506a(10) =292759a(11) =444680a(12) =653957a(13) =935472a(14) =1306483a(15) =1786806a(16) =2398979a(17) =3168444a(18) =4123729a(19) =5296612a(20) =6722303a(21) =8439626a(22) =10491183a(23) =12923536a(24) =15787389a(25) =19137752a(26) =23034123a(27) =27540670a(28) =32726395
External references
- oeis: A209487