Number of binary strings of length n with equal numbers of 0001 and 0111 substrings.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =14a(5) =24a(6) =42a(7) =72a(8) =126a(9) =228a(10) =420a(11) =792a(12) =1522a(13) =2948a(14) =5740a(15) =11200a(16) =21834a(17) =42524a(18) =82756a(19) =160960a(20) =313128a(21) =609624a(22) =1188180a(23) =2318976a(24) =4532442a(25) =8870628a(26) =17382264a(27) =34096896a(28) =66942960a(29) =131526888