Find the odd man out
1, 3, 10, 21, 64, 129, 356, 777
Choose the correct choice from the following answers:
A) 10  B) 21  C) 64  D) 356  E) 384
1*2+1= 
<gadget id="calculator">1*2+1</gadget>
<output>3</output>
3,3*3+1=10,10*2+1=21,21*3+1=64,64*2+1=129,129*3+1=388 but here it placed with 356, so it is wrong. starts with x*2+1,next x*3+1 alternately changes   ANSWER:356
<result>D</result>
Find the odd man out
1, 3, 10, 21, 64, 129, 356, 777