For those who have Mathematica and want to experiment with this, here's a quick function to generate the data: f[n_, base_] := Module[ {m, d, dp

For those who have Mathematica and want to experiment with this, here's a quick function to generate the data: f[n_, base_] := Module[ {m, d, dpairs}, d = Table[Last[IntegerDigits[Prime[i], base]], {i, 1, n}]; dpairs = Table[{d[[i]], d[[i + 1]]}, {i, 1, Length[d] - 1}]; Map[#[[1]] -> #[[2]] &, Tally[dpairs]] ] For the first n primes in a given base, it returns the mapping {i,j}->count for the all pairings of digit i followed by digit j. E.g., for the first million base 5 primes {2, 3} -> 68596 {3, 0} -> 1, {0, 2} -> 1, {2, 1} -> 64230 {1, 3} -> 77475 {3, 2} -> 72827 {2, 4} -> 77586 {4, 3} -> 64371 {3, 4} -> 79358 {4, 1} -> 84596 {1, 2} -> 79453 {4, 2} -> 58130 {4, 4} -> 42843 {1, 1} -> 42853 {3, 3} -> 39668 {2, 2} -> 39603 {1, 4} -> 50153 {3, 1} -> 58255