Number of step cyclic shifted sequences using exactly four different symbols.

A056417

Number of step cyclic shifted sequences using exactly four different symbols.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =3a(4) =12a(5) =136a(6) =204a(7) =1437a(8) =3520a(9) =20700a(10) =31956a(11) =317513a(12) =390364a(13) =2973536a(14) =8504720a(15) =32471391a(16) =61276740a(17) =622088400a(18) =790198476a(19) =6798297447a(20) =17290258088a(21) =79394956608a(22) =138325216092

External references