What kind of potato did you plant? Unsprouted store bought potato or seed potato with eyes? Either way, it doesn't look normal to me.
North Dakota State University has a checklist for potato emergence problems with pictures.
potato emergence problems
I saw this photo of "candelabra sprouting" and it looks similar to yours. Check out the article in the link here.
growing produce
Do you have any university extension office nearby to help with diagnosis?