@sequences = ('AGAGTATATACA', 'AGAGATATCCACACAC', 'CCCATAATATATAT', 'GAGAGAAAAAAA');

$seq_number = 0;
for $seq (@sequences) {
  $seq_number++;
  $qual = 'i' x length($seq);
  print ">seq-$seq_number\n$seq\n+\n$qual\n";
}

>seq-1
AGAGTATATACA
+
iiiiiiiiiiii
>seq-2
AGAGATATCCACACAC
+
iiiiiiiiiiiiiiii
>seq-3
CCCATAATATATAT
+
iiiiiiiiiiiiii
>seq-4
GAGAGAAAAAAA
+
iiiiiiiiiiii