A107691 Primes with digital product = 5.

5, 151, 1151, 1511, 511111, 1111151, 115111111, 1111115111, 1115111111, 1151111111, 111111111511, 111511111111, 1111151111111, 5111111111111, 111111151111111, 111151111111111, 5111111111111111, 111115111111111111111, 1111111111111111111511

Offset: 1

Author

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

Keywords

• base
• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A004022, A107612, A107689, A107690, A107692, A107693, A107694, A107695, A107696, A107697, A107698.

Programs

Magma

[p: p in PrimesUpTo(3*10^8) | &*Intseq(p) eq 5]; // Vincenzo Librandi, Jul 27 2016

Maple

select(isprime,[seq(seq((10^m-1)/9 + 4*10^j,j=0..m-1),m=1..40)]); # Robert Israel, Jan 03 2017

Mathematica

Flatten[ Table[ Select[ Sort[ FromDigits /@ Permutations[Flatten[{5, Table[1, {n}]} ]]], PrimeQ[ # ] &], {n, 0, 21}]]
Select[Prime[Range[3 10^6]], Times@@IntegerDigits[#] == 5 &] (* Vincenzo Librandi, Jul 27 2016 *)