find the value of 4.4!+ 5.5!+…….+n.n! July 24, 2020 0 4.4! can be written as (5!-$!), similary5.5!=(6!-5!), 6.6! = (7!-6! ) and so on . Thus by 4.4! + 5!+….+n.n! = (5!-4!) +(6!-5!)+(7!-6!) +……..+ (n+1)!-n! = (n+1)!-4! . Spread the knowledge..!! math teasersequence & series