1,1

a(4)=10111 because 10111 is the smallest prime with four duplicate digits.

Table[ First[ Select[ Prime[ Range[100000]], Max[ DigitCount[ # ]]==i & ]], {i, 6}] (* or *)

f[n_, b_] := Block[{k = 10^(n + 1), p = Permutations[ Join[ Table[ b, {i, 1, n}], {x}]], c = Complement[ Table[j, {j, 0, 9}], {b}], q = {}}, Do[q = Append[q, Replace[p, x -> c[[i]], 2]], {i, 1, 9}]; r = Min[ Select[ FromDigits /@ Flatten[q, 1], PrimeQ[ # ] & ]]; If[ r != Infinity, r, While[ !PrimeQ[k] || Count[ IntegerDigits[k], b] != n, k++ ]; k]]; Table[ f[n, 1], {n, 2, 18}]

Cf. A034388, A037055, A065584, A065821.

Sequence in context: A000886 A128855 A011825 this_sequence A034388 A131316 A062636

Adjacent sequences: A084670 A084671 A084672 this_sequence A084674 A084675 A084676

nonn,base

Harvey P. Dale (hpd1(AT)nyu.edu), Jun 29 2003

Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 03 2003