Sigma of factorial function?

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How would you find this sum mathmatically?$$\sum_{i=0}^\infty \left( \dfrac{1}{2} \right) ^{i!}$$

What techniques would you use to solve this as well?

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This is a Liouville number It is transcendental. As factorials grow extremely rapidly, it converges very fast. I would sum a few terms (until you get tired) and call it good. Alphagives 1.26562506... I quit after $i=10$-it wouldn't do $15$. As $11!=39,916,800$ these decimals should be good