What will be next number in this series. 2, 5, 9, 19, 37,__

Hi,

I feel the answer should be 75 not 73.

As the series is +1 and -1 in alternate

2*2 = 4 + 1 (5)
5*2=10-1 (9)
9*2=18+1 (19)
19*2=38-1 (37)
37*2=74-1 (73)

The last should be 37*2=74+1 (75).

Thanks,
Elan