the sum of first n terms of the series 1square + 2* 2square + 3square +2*4square + 5square + 2*6square +... is n*(n+1)square/2 when n is even. What is the sum when is odd?
the sum of first n terms of the series 12+2*22+32+2*42+52+2*62+... is (n(n+1)2)/2 when n is even. What is the sum when n is odd?
I have retried to explain my question, so, kindly answer my question as early as possible.
for your reference its question number 25 on page number 6.38 from objective mathematics by R.D. Sharma.