The first fifteen issues are found among Four Color (Dell, 1942 series) numbers 25, 54, 85, 130, 154, 198, 216, 240, 258, 280, 297, 326, 345, 358, 383 and 409.
There are actually sixteen predecessor Four Color issues, so the numbering is off by one.
"Walter Lantz Andy Panda" on cover and the indicia title is "Walter Lantz ANDY PANDA".