s0=
1
0
;s1=
0
1
;​​​​v[i_]:=Transpose[{UnitVector[3,i]}];​​​​L=Sum[Sum[aKroneckerProduct[s0,v[n+1],v[m+1]]+bKroneckerProduct[s1,v[n+2],v[m+2]],{n,0,1}],{m,0,1}];​​MatrixForm[L.Transpose[L]]
2
a
2
a
0
2
a
2
a
0
0
0
0
0
0
0
0
ab
ab
0
ab
ab
2
a
2
a
0
2
a
2
a
0
0
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0
0
0
0
0
ab
ab
0
ab
ab
0
0
0
0
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0
0
0
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0
0
0
0
0
0
0
0
0
2
a
2
a
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2
a
2
a
0
0
0
0
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0
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0
ab
ab
0
ab
ab
2
a
2
a
0
2
a
2
a
0
0
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0
0
0
ab
ab
0
ab
ab
0
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ab
ab
0
ab
ab
0
0
0
0
0
0
0
0
2
b
2
b
0
2
b
2
b
ab
ab
0
ab
ab
0
0
0
0
0
0
0
0
2
b
2
b
0
2
b
2
b
0
0
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ab
ab
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2
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2
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2
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ab
ab
0
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ab
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0
2
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2
b
0
2
b
2
b