Matematically cyle backwards and fowards a table

local currentIndex = 1

local arr = {1,2,3,4,5,6}


for index = currentIndex, 11 do
    print( #arr+1 - index)
end

local  index=1
local maxIndexs=9

for i=1,20 do
    index = index%(maxIndexs)-1 print(index+2)
end