/*
www-ATLAS of Group Representations.
3.L3(4):2a represented as 21 x 21 matrices over GF(7).
*/

F:=GF(7);

x:=CambridgeMatrix(1,F,21,[
"010000000000000000000",
"100000000000000000000",
"000010000000000000000",
"000000100000000000000",
"001000000000000000000",
"000000001000000000000",
"000100000000000000000",
"000000000001000000000",
"000001000000000000000",
"000000000000010000000",
"000000000000001000000",
"000000010000000000000",
"000000000000000001000",
"000000000100000000000",
"000000000010000000000",
"000000000000000000001",
"435420310366141116006",
"000000000000100000000",
"256515232654112506102",
"253041036004100306014",
"000000000000000100000"]);

y:=CambridgeMatrix(1,F,21,[
"001000000000000000000",
"000100000000000000000",
"000001000000000000000",
"000000010000000000000",
"106610010000000000000",
"000000000100000000000",
"000000000010000000000",
"460240060000000000000",
"000000000000100000000",
"100000000000000000000",
"000000000000000100000",
"000000000000000010000",
"000000000000000000100",
"000000000000000000010",
"552234141603063355310",
"666215242003020050656",
"421141230346030500166",
"263243043416254264241",
"152630044023110610251",
"563354422402060640616",
"532633166562120010543"]);

G<x,y>:=MatrixGroup<21,F|x,y>;
print "Group G is 3.L3(4):2a < GL(21,GF(7))";