Frequencies versus distances.

We might expect strong relationship between eg average distance between 1 and  7 (in that order) and the number of times 1,7 (in that order) occurs in last digit tables.

look for pair frequency
-- 351 795 860 380
-- 508 307 716 870
-- 629 696 311 775
-- 899 603 523 365
NR =  9592
Sums are  2386 2401 2411 2390
Proportions for 1,x are: 0.147108 0.333194 0.360436 0.159262
Proportions for 3,x are: 0.211579 0.127863 0.298209 0.362349
Proportions for 7,x are: 0.260888 0.288677 0.128992 0.321443
Proportions for 9,x are: 0.376151 0.252301 0.218828 0.15272
<<< Process finished (PID=18032). (Exit code 0)
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We could start by looking at tables above.