sub gcd {
($m,$n) = @_;
while (($r = ($m % $n)) !=0) { $m = $n; $n = $r; }
return $n;
}

sub seq {
  my ($last, $n) = @_;
  $last + gcd($n, $last)
}

my $x = 7;
my $i = 1;

while (1) {
  ++$i;
  my $oldx = $x;
  $x = seq($x, $i);
  my $y = $x - $oldx;
  print "$y\n";
}