0,1

a(5) = 1399 and the digital product is 3^5.

NextPrim[n_] := Block[{k = n + 1}, While[ ! PrimeQ[k], k++ ]; k]; a = Table[0, {18}]; p = 2; Do[q = Log[3, Times @@ IntegerDigits[p]]; If[q != 0 && IntegerQ[q] && a[[q]] == 0, a[[q]] = p; Print[q, " = ", p]]; p = NextPrim[p], {n, 1, 10^9}]

For a(23): a = Map[ FromDigits, Join[{0}, # ] & /@ Permutations[{1, 3, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 }]]; Min[ Select[a, PrimeQ[ # ] & ]]

For a(11): a = Map[ FromDigits, Permutations[{2, 6, 8, 8, 8, 9, 9, 9, 9, 9}]]; Min[ Select[a, PrimeQ[ # ] & ]]

Cf. A089365, A090840, A091465, A090841, A089298.

Sequence in context: A110406 A110434 A110798 this_sequence A107598 A087100 A102380

Adjacent sequences: A088650 A088651 A088652 this_sequence A088654 A088655 A088656

base,nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 22 2003