Three of the following four are alike in a certain way and thus form a group. Which is the one that does NOT belong to that group?
NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13-Operations on 13 such as adding /deleting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)

Correct option is A

Logic = second number  – first Number ×5+1
third  number - second number×5+1
option a= 9-44-218
9 × 5 + 1 = 46≠ 44
Hence it is wrong.
option b = 6-31-156
6 × 5 + 1 = 31 correct
31 × 5 + 1 = 156 correct
option c =13-66-331:
13 × 5 + 1 = 66 correct
66 × 5 + 1 = 331 correct
option d = 16-81-406:
16 × 5 + 1 = 81 correct
81× 5 + 1 = 406 correct

hence all option correctly follows the given logic except option a

hence option is odd one out.