Do these have anything to offer? They do the same thing in slightly different ways. Both let you start your sequence where you like.

$l = a;   #or whatever letter you want to start with
for my $n (1..28) {print $l; $l++; $l=substr($l,0,1)}    

$l = a;   #or whatever letter you want to start with
for my $n (1..28) {print $l; $l eq 'z' ? $l = 'a' : $l++ }
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§ George Sherston