Seven Circles Money-Coutts theorem
Given a triangle P1;P2;P3, consider the following chain of circles: c1 is inscribed in the angle P1; c2 inscribed in the angle P2 and tangent to c1; c3 inscribed in the angle P3 and tangent to c2; etc. This process is 6-periodic: c7 == c1 (?) It's a version of Six (Seven) Circles Money-Coutts theorem.
Some tip: If inscribed circle tangent to extension of side, periodicity appears later, than c7.