Lots of extraneous code; you can get rid of "new int[]" for example, and you never need use println to print an empty
String.
Your gridwidth and max/min indices are also necessary. I would suggest you can print spaces up to the count. That way you only need two nested loop levels, rather than three. Your thing about odd numbers and even numbers looks complicated, and is probably incorrect. The easiest way to test whether a number is odd is
That works for positive and negative numbers, and the right operand of the & can be one of a restricted set of numbers. I'll let you work it out for yourself which numbers.
Clean, efficient and simple? Afraid not.