tau* ( m -- n )

Vocabulary

project-euler.common

Inputs

m

an object

Outputs

n

an object

Definition

USING: kernel math math.functions ranges sequences ;

IN: project-euler.common

: tau* ( m -- n )
    factor-2s dup
    [ 1 + ] [ perfect-square? -1 0 ? ]
    [ dup sqrt >fixnum [1..b] ] tri*
    [ dupd divisor? [ [ 2 + ] dip ] when ] each drop * ;