How to find the harmonic mean of an infinite series that goes like this "1+1/2+1/6+1/12+1/20+1/30+....…

Remember that the harmonic of any number of quantities is the reciprocal of the arithmetic mean( simple average ) of their own reciprocals. So, here, H.M. will be lim n->(infinity) of n / ( 1 + 2 + 6 +... + A(n) ) Now you can find the sum-series by using any simple convential method like the method of differences, which I ume you'd know already.. So try