Number of reversible strings with n-1 beads of 2 colors. 4 beads are black. String is not palindromic.

A032091

Number of reversible strings with n-1 beads of 2 colors. 4 beads are black. String is not palindromic.

Terms

    a(0) =2a(1) =6a(2) =16a(3) =32a(4) =60a(5) =100a(6) =160a(7) =240a(8) =350a(9) =490a(10) =672a(11) =896a(12) =1176a(13) =1512a(14) =1920a(15) =2400a(16) =2970a(17) =3630a(18) =4400a(19) =5280a(20) =6292a(21) =7436a(22) =8736a(23) =10192a(24) =11830a(25) =13650a(26) =15680a(27) =17920a(28) =20400a(29) =23120

External references