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A028843 Numbers n such that iterated product of digits of n is a prime. 6
2, 3, 5, 7, 12, 13, 15, 17, 21, 26, 31, 34, 35, 37, 43, 51, 53, 57, 62, 71, 73, 75, 112, 113, 115, 117, 121, 126, 131, 134, 135, 137, 143, 151, 153, 157, 162, 171, 173, 175, 211, 216, 223, 232, 261, 278, 279, 287, 297, 299, 311, 314, 315, 317, 322, 341, 351, 355 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

E.g. 53 -> 5*3 = 15 -> 1*5 = 5 is a prime.

MATHEMATICA

a[n_]:=NestWhile[Times@@IntegerDigits[#]&, n, #>9&]; Select[Range[355], PrimeQ[a[#]]&] (* Jayanta Basu, Jun 02 2013 *)

CROSSREFS

Cf. A031347, A028842, A028835.

Sequence in context: A114983 A118950 A092620 * A028842 A260181 A140971

Adjacent sequences:  A028840 A028841 A028842 * A028844 A028845 A028846

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Patrick De Geest, Jun 15 1999

Corrected by Franklin T. Adams-Watters, Jan 17 2007

STATUS

approved

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Last modified October 23 17:32 EDT 2019. Contains 328373 sequences. (Running on oeis4.)