What is next number in this series? 1, 3, 4, 8, 15, 27,_

Number 4 in the series is formed = 1+3
Number 8 in the series is formed = 1+3+4
Number 15 in the series is formed = 3+4+8
Number 27 in the series is formed = 4+8+15

So next number is 8+15+27 =50.