You can write it asHi everyone! Today we were asked to say if this particular series converges or diverges : . The first thing I though about is to find if the partial sum converges in to something, but the thing is, I can't find a formula to define the nth partial sum of the particular series. It looks like the denominator is just but I can't understand why the first summand would be only one where as all the other summands seem to be multiplied by 10. Anyone got any idea on how to find the formula for the partial sum or at least have another method to prove its convergence or divergence? Thanks everyone in advance!