let us consider 5+7+4=36 47 30
first two digits come from ([5+1]*4)+(5+7)=36
then next 2 digits come from [5*(7+1)]+7=47
the last 2 come from 5*(5+1)=30
Similarly if we do for 7+3+5,we get
first 2 digits are ([7+1]*5)+(7+3)=50
next 2 are [7*(3+1)]+3=31
last 2 are 7*(7+1)=56
therefore answer is 503156....
first two digits come from ([5+1]*4)+(5+7)=36
then next 2 digits come from [5*(7+1)]+7=47
the last 2 come from 5*(5+1)=30
Similarly if we do for 7+3+5,we get
first 2 digits are ([7+1]*5)+(7+3)=50
next 2 are [7*(3+1)]+3=31
last 2 are 7*(7+1)=56
therefore answer is 503156....