A107694 - OEIS

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A107694

Primes with digital product = 8.

181, 241, 421, 811, 1181, 1811, 2141, 2221, 2411, 4211, 8111, 21221, 141121, 142111, 411211, 1111181, 1112141, 1121221, 1211141, 1211411, 1212121, 2111411, 2121121, 2211211, 2221111, 2411111, 4121111, 4211111, 11221211, 12111221, 12121121

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..31.

MATHEMATICA

Union[ Flatten[ Table[ Select[ Sort[ FromDigits /@ Join[ Permutations[ Flatten[{8, Table[1, {n}]}]], Permutations[ Flatten[{2, 4, Table[1, {n - 1}]}]], Permutations[ Flatten[{2, 2, 2, Table[1, {n - 2}]}] ]]], PrimeQ[ # ] & ], {n, 0, 7}]]]

Select[Prime[Range[3 10^6]], Times@@IntegerDigits[#] == 8 &] (* Vincenzo Librandi, Jul 27 2016 *)

PROG

(Magma) [p: p in PrimesUpTo(3*10^7) | &*Intseq(p) eq 8]; // Vincenzo Librandi, Jul 27 2016

CROSSREFS

Cf. A004022, A107612, A107689, A107690, A107691, A107692, A107693, A107695, A107696, A107697, A107698.

Sequence in context: A142519 A053140 A330366 * A142312 A020360 A238670

Adjacent sequences: A107691 A107692 A107693 * A107695 A107696 A107697

KEYWORD

base,nonn

AUTHOR

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

STATUS

approved