A051195 T(2n+2,n), array T as in A050186; a count of aperiodic binary words.

0, 4, 12, 56, 200, 792, 2968, 11440, 43632, 167960, 646184, 2496144, 9655984, 37442160, 145416240, 565722720, 2203937120, 8597496600, 33577908232, 131282408400, 513791254704, 2012616400080, 7890369761872, 30957699535776

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Formula

C(2n+2, n)-[n even]*C(n+1, n/2). - Ralf Stephan, Mar 19 2004

Conjecture: -(n+2)*(n-1)*a(n) +2*(n+1)*(3*n-4)*a(n-1) +4*(-n^2+5*n-1)*a(n-2) -8*n*(3*n-4)*a(n-3) +16*(n-1)*(2*n-5)*a(n-4)=0. - R. J. Mathar, May 20 2013