Question

The next item in the series 13,25,51,101,203is

Answer 1

405 is the answer

13 + 12 = 25

25 + 26 = 51 (12*2 + 2 = 26)

51 + 50 = 101 (26*2 - 2 = 50)

101 + 102 = 203 (50*2 + 2 = 102)

203 + 202 = 405 (102*2 - 2 = 202)

Answer 2

Hello dear,


13 + 12 = 25

25 + 26 = 51 (12×2 + 2 = 26)

51 + 50 = 101 (26×2 - 2 = 50)

101 + 102 = 203 (50×2 + 2 = 102)

203 + 202 = 405 (102×2 - 2 = 202)


Hope it helps.