solutions of T^11 ...:
r: 3.73817237526596236943, r/4: 0.934543093816490592358; 4R: 6.49758795666964225060, R: 1.62439698916741056265
r: 3.90557187017249978843, r/4: 0.976392967543124947108; 4R: 7.44234789273771796573, R: 1.86058697318442949143
r: 3.99025730741338356884, r/4: 0.997564326853345892209; 4R: 7.94163876453913872378, R: 1.98540969113478468094