Order of universal Chevalley group D_2(q), q = prime power.

Terms

a(0) =36a(1) =576a(2) =3600a(3) =14400a(4) =112896a(5) =254016a(6) =518400a(7) =1742400a(8) =4769856a(9) =16646400a(10) =23970816a(11) =46785600a(12) =147476736a(13) =243360000a(14) =386358336a(15) =593409600a(16) =885657600a(17) =1071645696a(18) =2561979456a(19) =4744454400a(20) =6314527296