: count-factor ( n d -- n' c )
[ 1 ] 2dip [ /i ] keep
- [ dupd /mod zero? ] curry [ nip [ 1+ ] dip ] while drop
+ [ dupd /mod zero? ] curry [ nip [ 1 + ] dip ] while drop
swap ;
: write-factor ( n d -- n' d' )
: totient ( n -- t )
{
{ [ dup 2 < ] [ drop 0 ] }
- [ dup unique-factors [ 1 [ 1- * ] reduce ] [ product ] bi / * ]
+ [ dup unique-factors [ 1 [ 1 - * ] reduce ] [ product ] bi / * ]
} cond ; foldable
: divisors ( n -- seq )