A107695 Primes with digital product = 9.

19, 191, 313, 331, 911, 11119, 111119, 111191, 113131, 131113, 131311, 911111, 1131113, 1131131, 1311131, 1311311, 3111131, 3113111, 11111119, 11111911, 11911111, 111111313, 111111331, 111113113, 111113131, 111131131, 111133111

Offset: 1

Author

Zak Seidov and Robert G. Wilson v, May 20 2005

Keywords

• base
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..9000

Crossrefs

Cf. A004022, A107612, A107689, A107690, A107691, A107692, A107693, A107694, A107696, A107697, A107698.

Programs

Magma

[p: p in PrimesUpTo(3*10^7) | &*Intseq(p) eq 9]; // Vincenzo Librandi, Jul 27 2016

Mathematica

Union[ Flatten[ Table[ Select[ Sort[ FromDigits /@ Join[ Permutations[ Flatten[{9, Table[1, {n}]}]], Permutations[ Flatten[{3, 3, Table[1, {n - 1}]}]]]], PrimeQ[ # ] & ], {n, 0, 8}]]]
Select[Prime[Range[3 10^6]], Times@@IntegerDigits[#] == 9 &] (* Vincenzo Librandi, Jul 27 2016 *)