Question Number 214111 by issac last updated on 28/Nov/24
$$\mathrm{hmmmm}............ \\ $$$$\mathrm{can}\:\mathrm{we}\:\mathrm{find}\:\mathrm{closed}\:\mathrm{form}\:\mathrm{of}\:\mathrm{sum} \\ $$$$\underset{{j}=\mathrm{0}} {\overset{\infty} {\sum}}\:\frac{\mathrm{1}}{\mathrm{2}^{\mathrm{2}^{{j}} } }\:??\:\mathrm{or}\:\mathrm{any}\:\mathrm{idea}..? \\ $$