Number of reversible strings with n-1 beads of 2 colors. 7 beads are black. String is not palindromic.

A032094

Number of reversible strings with n-1 beads of 2 colors. 7 beads are black. String is not palindromic.

Terms

    a(0) =4a(1) =16a(2) =60a(3) =160a(4) =396a(5) =848a(6) =1716a(7) =3200a(8) =5720a(9) =9696a(10) =15912a(11) =25152a(12) =38760a(13) =58080a(14) =85272a(15) =122496a(16) =173052a(17) =240240a(18) =328900a(19) =443872a(20) =592020a(21) =780208a(22) =1017900a(23) =1314560a(24) =1682928a(25) =2135744a(26) =2689808a(27) =3361920a(28) =4173840a(29) =5147328

External references