I once planted corn, outside very close together, about 2 inches apart, in four foot rows, less than 2 feet apart.
I got very tall, healthy corn with very, very few cobs, really very tall grass.
A bigger pot without spacing change may do little.
Corn does not like being transplanted, so if you do and it goes pfft, that is normal.
My cousin transplanted some from his garden to mine successfully but it produced no or stunted ears.
