Here's the question you clicked on:
fazee4u
-1, 2 ,12, 40 what will be the next term? please reply quick
0,3,13,41 if we shift it but i dont see a pattern in it at the moment
3 10 28 7 18 9 not enough terms to determine it that way either
-1+1=0 (zero at 40)....2+2=4(4 at 40)...maybe that's some kind of the pattern...I guess not...
did they give u any option on this question
http://www.wolframalpha.com/input/?i=-1%2C+2%2C+12%2C+40%2C+...
There are lots of patterns you could fit to this sequence. One pattern is as follows:\[a_n=(2n-1)\times2^n\]for \(n=0,1,2...,\infty\)