[Jprogramming] New to J/problem 28

[Ralph G Selfridge]

Relative to spirals and sums of diagonals it can be shown that
the last digit in any answer is:
If 1=10|n   1
if 3=10|n   5
if 5=10|n   1
if 7=10|n   7
if 9=10|n   1

Ralph S