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!2*(n=scan())-sum(which(!n%%1x=1:n))%*%!n%%x
Try it online!Try it online!
Returns TRUE for perfect numbers ansand FALSE for imperfect ones.
TRUE
FALSE
!2*(n=scan())-sum(which(!n%%1:n))
Try it online!
Returns TRUE for perfect numbers ans FALSE for imperfect ones.
!2*(n=scan())-(x=1:n)%*%!n%%x
Returns TRUE for perfect numbers and FALSE for imperfect ones.
