local fn IsPrime( n as long ) as BOOL
  BOOL result = YES
  long i

  if ( n < 2 ) then result = NO : exit fn
  for i = 2 to n + 1
    if ( i * i <= n ) and ( n mod i == 0 )
      result = NO : exit fn
    end if
  next
end fn = result

local fn Mobius( n as long ) as long
  long i, p = 0, result = 0

  if ( n == 1 ) then result = 1 : exit fn
  for i = 1 to n + 1
    if ( n mod i == 0 ) and ( fn IsPrime( i ) == YES )
      if ( n mod ( i * i ) == 0 )
        result = 0 : exit fn
      else
        p++
      end if
    end if
  next
  if( p mod 2 != 0 )
    result = -1
  else
    result = 1
  end if
end fn = result

window 1, @"Möbius function", (0,0,600,300)

printf @"First 100 terms of Mobius sequence:"

long i
for i = 1 to 100
  printf @"%2ld\t", fn Mobius(i)
  if ( i mod 20 == 0 ) then print
next

HandleEvents