A144596 Christoffel word of slope 2/7.

0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0

Offset: 0

Author

N. J. A. Sloane, Jan 13 2009

Keywords

• nonn
• easy

Comments

The path is on the slope after 0, 9, 18, 27, 36 ,.... (A008591) steps, which gives the C-finite recurrence.

Crossrefs

See A144595 for further details.

Formula

a(n) = a(n-9). - R. J. Mathar, May 28 2025

G.f.: -x^4*(1+x^4) / ( (x-1)*(1+x+x^2)*(x^6+x^3+1) ). - R. J. Mathar, May 28 2025