<prompt> Pata jumla ya frac2141 - 1 frac2242 - 1 frac2444 - 1 frac2848 - 1 cdots.  <response>: Ona kwamba frac22k42k - 1 frac22k 142k - 1 - frac142k - 1 frac122k-1 - frac142k- 1 frac142k-1-1 - frac142k-1.Kwa hivyo, jumla ya darubini kama kushotofrac142-1-1 - frac1420-1kulia kushotofrac 1420-1 - frac1421-1kulia kushotofrac1421 -1 - frac1422-1kulia cdotsna kutathmini hadi 142-1-1 1 . 