Question 16117
there are 2 patterns here:


1. the squaring of the "counter" 1,2,3,4,5, etc
2. the -1,1,3,5,7, pattern which is basically a x2 table (2,4,6,8,10) just "shifted.


OK then:
1. if the counter is n, then we have n^2. 
2. x2 table is 2n, but ours is shifted, so that first number (should be 2) is now -1.... ie 2n-3


So combine them, we have {{{n^2 - (2n-3)}}}
{{{n^2 - 2n + 3}}}


Check...at random, let n=5 (answer should be 18)


We have 5^2 - 2*5 + 3
--> 25 - 10 + 3
--> 15 + 3
--> 18


jon.