You could use a closure

sub seq {
  my($v, $i) = ($_[0], $_[1] || 5);
  my $n = 0;

  return sub { $n ? ($n += $i) : ($n = $v) };
}

my $iter = seq 8 % 3, 5;

print join ', ' => map $iter->(), 1 .. 5;

print " ...\n";

$iter = seq 8 % 5;

print join ', ' => map $iter->(), 1 .. 5;

print " ...\n";

__output__

2, 7, 12, 17, 22 ...
3, 8, 13, 18, 23 ...
[download]

So we start out with the initial value of the first argument and then increment by the second argument or 5 by default.
HTH

_________
broquaint

update: dropped block as first argument as it was rather unnecessary