Number of 2n-bead black-white reversible complementable strings with n black beads and fundamental period 2n.
A045631
Number of 2n-bead black-white reversible complementable strings with n black beads and fundamental period 2n.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =20a(5) =70a(6) =243a(7) =889a(8) =3276a(9) =12276a(10) =46435a(11) =176869a(12) =677022a(13) =2602197a(14) =10033212a(15) =38787495a(16) =150286400a(17) =583434322a(18) =2268848988a(19) =8836447021a(20) =34461894010a(21) =134564992002a(22) =526025788992
External references
- oeis: A045631