Prime Crossword

3,7

1,1

37 and 11 are primes. As 31 and 71.

Can you produce a bigger one than 2×2? 5×5 perhaps, or even larger “prime crossword”? In decimal, binary, hexadecimal or whatever notation.

You might discuss it here:

http://lesswrong.com/r/discussion/lw/pf6/open_thread_september_18_september_24_2017/dxcr