1,1

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, p = Permutations[ Join[ Table[ b, {i, 1, n}], {x, y}]]; q = {}; Do[q = Append[q, Replace[p, {x -> c[[i]], y -> c[[j]]}, 2]], {i, 1, 9}, {j, 1, 9}]; Min[ Select[ FromDigits /@ Flatten[q, 1], PrimeQ[ # ] & ]]]]; Table[ f[n, 3], {n, 1, 18}]

Different from A065580.

Cf. A065586, A065580, A037058, A034388, A036507-A036536.

Cf. A037053, A037055, A037057, A037061, A037063, A037065, A037067, A037069, A037071.

Sequence in context: A099426 A100201 A159807 this_sequence A065580 A072320 A162603

Adjacent sequences: A037056 A037057 A037058 this_sequence A037060 A037061 A037062

nonn,base

Patrick De Geest (pdg(AT)worldofnumbers.com), Jan 04 1999.

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 23 2003