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

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: A320059 A270450 A270461 * A288099 A288103 A286729

Adjacent sequences: A046419 A046420 A046421 * A046423 A046424 A046425

Keyword

nonn,base

Author

Patrick De Geest, Jun 15 1998

Extensions

Edited by Charles R Greathouse IV, Apr 28 2010

Status

approved