find the pattern: 1, 2, 5, 26
The series is based on following pattern :
$latex \left ( 1 \right )^{2}+1=2$ $latex \left ( 2 \right )^{2}+1=5$ $latex \left ( 5 \right )^{2}+1=26$ $latex \left ( 26 \right )^{2}+1=677$ Therefore, the next number of this series will be 677.
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+5 
