Number of strong starters in cyclic group of order 2n+1.

Terms

a(0) =0a(1) =0a(2) =2a(3) =0a(4) =4a(5) =8a(6) =32a(7) =224a(8) =800a(9) =6660a(10) =27554a(11) =158680a(12) =1201626a(13) =9415980a(14) =76761968a(15) =672858900a(16) =6015305136a(17) =59514095596