Title might not make complete sense, couldn't think of a way to explain it so I will do a mock PHP example.
<?php
$startNumber = 1;
$endNumber = 15;
$fileExt = '.jpg';
?>
And then on the page it will echo from the $startNumber to the $endNumber in something like a foreach
<?php echo("<img src=\"#.jpg\">"); ?>
Hope this is making sense...
I'd also like to point out that the numbers < 10 start with a 0 so it will need to be in the image source link.