Number of 5-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209117
Number of 5-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
Terms
- a(0) =5a(1) =63a(2) =261a(3) =741a(4) =1683a(5) =3325a(6) =5935a(7) =9835a(8) =15397a(9) =23039a(10) =33209a(11) =46421a(12) =63227a(13) =84225a(14) =110055a(15) =141411a(16) =179025a(17) =223687a(18) =276217a(19) =337489a(20) =408427a(21) =490001a(22) =583211a(23) =689123a(24) =808841a(25) =943515a(26) =1094337a(27) =1262553a(28) =1449447a(29) =1656361
External references
- oeis: A209117