164083

when investigating the sequence I noticed that the difference between the terms when up by one each time starting with +2 then plus 3 then plus 4 etc. because this is not an arithmetic sequence I am un able to use nth term to accurately find out how many rectangles would be in a stick with 1000 yellow and blue pieces. I have only worked up to ten. 1=1 2=3 3=6 4=10 5=15 6=21 7=28 8=36 9=45 and 10=55