$$\sum_{k=1}^{\infty}\ln(\frac{(k + 1) (k + 3)}{(k + 2) ^ 2})$$
The answer is = ln(2/3)
Can you please help me?
Sum[Log[((k + 1)*(k + 3))/(k + 2)^2], {k, 1, Infinity}]
yields -Log[3/2] or Log[2/3] or Log[2]-Log[3].
That is what Wolfram Mathematica and WolframAlpha do.
Of course, I may have missed something.
Sum[Log[(k + 1) (k + 3)/(k + 2)^2], {k, 1, Infinity}]
does the job nicely. $\endgroup$