Need a program for this condition!

Question

Input
3 1 2 3
Output
53
Explanation
Possible ways of buying sweets are-
a) 1
b) 1 2
c) 2
d) 1 2 3
e) 2 3
f) 3 cost of each of these is following-
a) 1*1= 1
b) 1*2+2*2= 6
c) 2*2= 4
d) 1*3+2*3+3*3= 18
e) 2*3+3*3= 15
f) 3*3= 9

Answer 1

https://code.sololearn.com/W7PNm8vZ0M7P/?ref=app

Something like that?

Answer 2

https://code.sololearn.com/W7oI2e0X0Dr8/?ref=app

Or maybe with more parameters and not all because I dont know exactly logical about the series