() urgent!) sequence 4, - 1, 10 / 17, - 13 / 31, 16 / 49 The general term formula of

() urgent!) sequence 4, - 1, 10 / 17, - 13 / 31, 16 / 49 The general term formula of

an=[(3n+1)(-1)^(n+1)]/(2n^2-1)