Number of symmetrically inequivalent coincidence rotations of icosian ring of index n.

Terms

a(0) =1a(1) =0a(2) =0a(3) =25a(4) =36a(5) =0a(6) =0a(7) =0a(8) =100a(9) =0a(10) =288a(11) =0a(12) =0a(13) =0a(14) =0a(15) =440a(16) =0a(17) =0a(18) =800a(19) =900a(20) =0a(21) =0a(22) =0a(23) =0a(24) =960a(25) =0a(26) =0a(27) =0a(28) =1800a(29) =0