A050189 T(n,4), array T as in A050186; a count of aperiodic binary words.

0, 5, 12, 35, 64, 126, 200, 330, 480, 715, 980, 1365, 1792, 2380, 3024, 3876, 4800, 5985, 7260, 8855, 10560, 12650, 14872, 17550, 20384, 23751, 27300, 31465, 35840, 40920, 46240, 52360, 58752, 66045, 73644, 82251, 91200

Offset: 4

Author

Clark Kimberling

Keywords

• nonn

Crossrefs

Cf. A006918, A050186.

Formula

Seems to be n * A006918.

From Chai Wah Wu, Jun 11 2016: (Start)

a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n > 11 (conjectured).

G.f.: x^5*(5 + 2*x + x^2)/((1 - x)^5*(1 + x)^3) (conjectured). (End)