diff --git a/gen_img.py b/gen_img.py
index d3c0d86d..8250663c 100644
--- a/gen_img.py
+++ b/gen_img.py
@@ -2508,7 +2508,7 @@ def main(args):
                     metadata.add_text("crop-left", str(crop_left))
 
                 if filename is not None:
-                    fln = filename
+                    fln = first_available_filename(args.outdir, filename) #Checks to make sure is not existing file, else returns first available sequential filename
                 else:
                     if args.use_original_file_name and init_images is not None:
                         if type(init_images) is list:
@@ -2586,7 +2586,8 @@ def main(args):
                     negative_scale = args.negative_scale
                     steps = args.steps
                     seed = None
-                    seeds = None
+                    if pi == 0:
+                        seeds = None
                     strength = 0.8 if args.strength is None else args.strength
                     negative_prompt = ""
                     clip_prompt = None
@@ -2670,6 +2671,8 @@ def main(args):
 
                             m = re.match(r"d ([\d,]+)", parg, re.IGNORECASE)
                             if m:  # seed
+                                if pi > 0 and len(raw_prompts) > 1: #Bypass od 2nd loop for dynamic prompts
+                                    continue
                                 seeds = [int(d) for d in m.group(1).split(",")]
                                 logger.info(f"seeds: {seeds}")
                                 continue
@@ -2802,7 +2805,11 @@ def main(args):
                             logger.error(f"Exception in parsing / 解析エラー: {parg}")
                             logger.error(f"{ex}")
 
-                # override Deep Shrink
+                # override filename to add index number if more than one image per prompt
+                if filename is not None and (args.images_per_prompt >  1 or len(raw_prompts) > 1):
+                    filename = filename + "_%s" % pi
+                    
+                # override Deep Shrink    
                 if ds_depth_1 is not None:
                     if ds_depth_1 < 0:
                         ds_depth_1 = args.ds_depth_1 or 3
@@ -2835,12 +2842,16 @@ def main(args):
                 # prepare seed
                 if seeds is not None:  # given in prompt
                     # num_images_per_promptが多い場合は足りなくなるので、足りない分は前のを使う
-                    # Previous implementation may result in unexpected behaviour when number of seeds is lesss than number of repeats. Last seed is taken for rest of repeated prompts
+                    # Previous implementation may result in unexpected behaviour when number of seeds is lesss than number of repeats. Last seed is taken for rest of repeated prompts. Add condition if last element is -1, to start randomizing seed.
                     if len(seeds) > 1:
                         seed = seeds.pop(0)
                     elif len(seeds)  == 1:
-                        seed = seeds.pop(0)
-                        seeds = None
+                        if seeds[0] == -1:
+                            seeds = None
+                        else:
+                            seed = seeds.pop(0)
+                        
+                        
                 else:
                     if args.iter_same_seed:
                         seed = iter_seed
@@ -2940,7 +2951,35 @@ def main(args):
 
     logger.info("done!")
 
+def first_available_filename(path, filename):
+    """
+    Checks if filename is in use.
+    if filename is in use, appends a running number
+    e.g. filename = 'file.png':
 
+    file.png
+    file_1.png
+    file_2.png
+
+    Runs in log(n) time where n is the number of existing files in sequence
+    """
+    i = 1
+    if not os.path.exists(os.path.join(path, filename)):
+        return filename
+    fileext = os.path.splitext(filename)
+    filename = fileext[0] + "_%s" + fileext[1]
+    # First do an exponential search
+    while os.path.exists(os.path.join(path,filename % i)):
+        i = i * 2
+
+    # Result lies somewhere in the interval (i/2..i]
+    # We call this interval (a..b] and narrow it down until a + 1 = b
+    a, b = (i // 2, i)
+    while a + 1 < b:
+        c = (a + b) // 2 # interval midpoint
+        a, b = (c, b) if os.path.exists(os.path.join(path,filename % c)) else (a, c)
+
+    return filename % b
 def setup_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser()