Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero and three times sum of squares <= n*(1)*(1+1).
A208798
Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero and three times sum of squares <= n*(1)*(1+1).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =3a(4) =3a(5) =15a(6) =22a(7) =38a(8) =147a(9) =296a(10) =526a(11) =2421a(12) =5017a(13) =10025a(14) =43986a(15) =96951a(16) =202141a(17) =880269a(18) =1993222a(19) =4317765a(20) =18453137a(21) =42777491a(22) =95192956a(23) =400944526a(24) =946008489a(25) =2151685046a(26) =8941940220a(27) =21409059701a(28) =49569448411a(29) =203582329338
External references
- oeis: A208798