Find the missing number of the series: 17, 16, 136, 38, 16, 418, 24, ?, 144

Question

What number should replace the question mark?

51 - - - 306

17 - - - 136

45 - - - 405

26 - - - 208

38 - - - ?

Answer 1

12

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the 5th number of the series should be 22 not 16, probably typo.
17 16 136
38 22 418
24 ?? 144
a b c, c=a*b/2
17*8/2=136, 38*22/2=418, 24*12/2=144