It seems as if the difference in the sum for the preceding 1-digit numbers are 1. i.e., you have to add 1 to 1+2+4=7(+1) = 8, then to get to 30 you have to add another 1, (1)+1+2+4+8+15=30. Then, for some reason, the difference becomes 10 to the negative. And seeing as the initial statement said that the next number in the sequence must be less than 150, I assume that there will simply be another digit added, and also to the negative, i.e. the sum of all the numbers minus 100.I will tell you if its 110 by tomorrow when he answers my email. Oh and big dog It doesnt double 4 more times since 50 is not two times 30. Boerseun how did you get 110 since the method is more important than the answer

You're right - I am by no stretch of the imagination a mathematician.