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

21249, 33271, 89937, 146461, 147833, 148519, 164297, 175257, 211631, 216953, 234269, 254849, 261023, 269941, 311229, 318033, 348823, 377001, 390447, 520209, 561491, 848239, 941679, 943679, 957447, 960957, 1012879, 1110159, 1221431, 1410399, 1525203, 1681729

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Example

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

Crossrefs

Cf. A217263, A217264, A180679, A181559.

Sequence in context: A284915 A252165 A289674 * A345563 A345564 A345819

Adjacent sequences: A217262 A217263 A217264 * A217266 A217267 A217268

Keyword

nonn,base

Author

Dmitri Kamenetsky, Sep 29 2012

Status

approved