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A217265 Numbers with 4 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime. 4

%I

%S 21249,33271,89937,146461,147833,148519,164297,175257,211631,216953,

%T 234269,254849,261023,269941,311229,318033,348823,377001,390447,

%U 520209,561491,848239,941679,943679,957447,960957,1012879,1110159,1221431,1410399,1525203,1681729

%N Numbers with 4 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime.

%e 21249 is 3*3*3*787. 333787, 337873, 378733 and 787333 are all prime, so 21249 is in the sequence.

%Y Cf. A217263, A217264, A180679, A181559.

%K nonn,base

%O 1,1

%A _Dmitri Kamenetsky_, Sep 29 2012

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Last modified April 2 02:09 EDT 2023. Contains 361723 sequences. (Running on oeis4.)