Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and first and second differences in -3..3.
A208965
Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and first and second differences in -3..3.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =29a(6) =87a(7) =325a(8) =1148a(9) =4168a(10) =15250a(11) =57027a(12) =214739a(13) =820038a(14) =3156251a(15) =12243837a(16) =47772129a(17) =187370511a(18) =738088612a(19) =2919087297a(20) =11585698838a(21) =46133010366a(22) =184243108172a(23) =737834327019
External references
- oeis: A208965