a1=
=1×3!×(3!×1 3
)11 3
a2=
=2×4!×(4!×2 32
)2=5!×(1 3
)2-4!×(1 3
)11 3
a3=
=3×5!×(5!×3 33
)3=6!×(1 3
)3-5!×(1 3
)21 3
…
a100=
=103×(102!×100 3100
)100-102!×(1 3
)991 3
所以,
+3!×1 3
+4!×2 32
+…+5!×3 33
102!×100 3100
=1×3!×(
)1+5!×(1 3
)2-4!×(1 3
)1+6!×(1 3
)3-5!×(1 3
)2+…+103×(1 3
)100-102!×(1 3
)991 3
=103!×(
)100-4!×1 3
+3!×
1 3