\
The sum is
.
\
The sigma notation is
.
\
Consider
.
\
The number of terms in sum is
.
\
.
\
\
The sigma notation is
.
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. ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=795da629f821d34178f5755812d039f2.png\")
.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
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.