Question 1034471
(1/2)n*(n+1) is the sum of all the numbers from 1 to n.
From 1 to 3 is a total of 6, so the answer would be the stack of 190 poles. We just ignore the first 3.
380=n(n+1)
n^2+n-380=0
(n+20)(n-19)=0
positive root only, n=19
16 layers, because we ignore the first 3.
4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19=184