What do you want to do with it? I'll do what I can: SUM = 1 - 4/5 - 3/5 - 8/17 - 5/13 - ...???? SUM = 2/2 - 4/5 - 6/10 - 8/17 - 10/26 - ...???? The sequence of absolute value of numerators is 2,4,6,8,10 The sequence of absolute value of denominators is 2,5,10,17,26 2,4,6,8,10 has general term 2n 1,5,10,17,26 has general term n2+1 The general term would beexcept for the first term being positive instead of negative, so we write the first term as SUM = 2 - 2/2 - 4/5 - 6/10 - 8/17 - 10/26 - ...???? So it could be written this way: SUM = The next term after -10/26 (or -5/13) would be It can't be summed to infinity because it diverges when compared to the harmonic p-series S(1/n). Edwin