What is the next number of the following sequence
21,77,165,285,......	Choose the correct choice from the following answers:
A) 434
B) 435
C) 436
D) 437
E) 438
21=5^2-4   77=9^2-4   165=13^2-4   285=17^2-4   5,9,13,17,21(+4)   in the same way next no. will be   21^2-4=441-4= 
<gadget id="calculator">441-4</gadget>
<output>437</output>
437   ANSWER:437
<result>D</result>
What is the next number of the following sequence
21,77,165,285,......