A046422 - OEIS

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A046422

Numbers requiring 2 steps to reach a prime under the prime factor concatenation procedure.

4, 9, 24, 30, 32, 36, 38, 42, 50, 55, 57, 60, 68, 74, 75, 88, 92, 94, 99, 102, 106, 108, 110, 122, 134, 140, 155, 158, 174, 194, 206, 209, 215, 231, 244, 254, 272, 280, 287, 298, 299, 306, 314, 323, 332, 334, 346, 351, 362, 365, 371, 374, 398, 413, 415, 417

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..56.

P. De Geest, Home Primes

EXAMPLE

24 = 2*2*2*3, 2223 = 3*3*13*19, 331319 is prime.

CROSSREFS

Cf. A037271, A046411.

Sequence in context: A373002 A270450 A270461 * A288099 A288103 A286729

Adjacent sequences: A046419 A046420 A046421 * A046423 A046424 A046425