A181559 Numbers with three distinct prime factors (each of which may or may not be repeated) which when concatenated in any order form a prime number.

3311, 23177, 27181, 32153, 36421, 41237, 53977, 86507, 110971, 125069, 142373, 162239, 190267, 208579, 254947, 256413, 288659, 298991, 353683, 377839, 400631, 500981, 543337, 593747, 769239, 776797, 853811, 875483, 901949, 964481, 996611, 1053787, 1135673

Offset

1,1

Comments

This is a superset of A180679 because in this sequence, unlike in A180679, any of the prime factors may (but need not) be repeated as a factor.

Links

Table of n, a(n) for n=1..33.

Mathematica

okQ[n_] := Module[{pfs = Transpose[FactorInteger[n]][[1]]}, Length[pfs] == 3 && And @@ PrimeQ[FromDigits /@ (Flatten /@ (IntegerDigits /@ Permutations[pfs]))]]; Select[Range[2100000], okQ]

Crossrefs

Cf. A180679, A217263, A217264, A217265.

Sequence in context: A320717 A106724 A239671 * A180679 A251900 A078348

Adjacent sequences: A181556 A181557 A181558 * A181560 A181561 A181562

Keyword

nonn,base

Author

Harvey P. Dale, Jan 29 2011

Status

approved