Number of necklaces with n beads of 5 colors, no 2 adjacent beads the same color.

A106367

Number of necklaces with n beads of 5 colors, no 2 adjacent beads the same color.

Terms

    a(0) =5a(1) =10a(2) =20a(3) =70a(4) =204a(5) =700a(6) =2340a(7) =8230a(8) =29140a(9) =104968a(10) =381300a(11) =1398500a(12) =5162220a(13) =19175140a(14) =71582940a(15) =268439590a(16) =1010580540a(17) =3817763740a(18) =14467258260a(19) =54975633976a(20) =209430787820a(21) =799645010860

External references