Number of 2-balanced binary words of length n with respect to the permutations of the symbols.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =31a(7) =60a(8) =111a(9) =205a(10) =364a(11) =647a(12) =1110a(13) =1908a(14) =3190a(15) =5345a(16) =8743a(17) =14352a(18) =23090a(19) =37232a(20) =59113a(21) =94079a(22) =147531a(23) =232073a(24) =360750a(25) =561692a(26) =865823a(27) =1338269a(28) =2047388a(29) =3139690