Question

$1,2,6,21,84,445$
which of the following does not follow the pattern in the series?

• A. $2$
• B. $6$
• C. $21$
• D. $84$

Answer 1

The correct option is D $84$

Series follows the pattern :
$1\times 1+1=2$,
$2\times 2+2=6$,
$6\times 3+3=21$,
$21\times 4+4=88$,
$88\times 5+5=445$,
$445\times 6+6=2676$.
Therefore, number $84$ should be replaced by $88$.