A124728 - OEIS

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A124728

Numbers n such that n, n+1, n+2 and n+3 are products of 4 primes.

4023, 7314, 9162, 12122, 12123, 16674, 19434, 19940, 23874, 24723, 29094, 33234, 35124, 35125, 39234, 42182, 42183, 44163, 45175, 46988, 49147, 51793, 52854, 52855, 54584, 54585, 54663, 58375, 63594, 64074, 64075, 64323, 64491, 64712

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OFFSET

1,1

COMMENTS

Subset of A045940 Numbers n such that factorizations of n through n+3 have same number of primes (including multiplicities). Cf. A124057, A124729 Numbers n such that n, n+1, n+2 and n+3 are products of exactly 3,5 primes. There are no numbers n such that n, n+1, n+2 and n+3 are products of exactly 6 primes(?)

LINKS

D. W. Wilson, Table of n, a(n) for n = 1..10000

EXAMPLE

4023=3^3*149, 4024=2^3*503, 4025=5^2*7*23, 4026=2*3*11*61 (all products of 4 primes).

MATHEMATICA

Transpose[Select[Partition[Range[65000], 4, 1], Union[PrimeOmega[#]] == {4}&]] [[1]] (* Harvey P. Dale, Nov 01 2011 *)

CROSSREFS

Cf. A045940, A124057, A124729.

Sequence in context: A236521 A235658 A186530 * A251098 A034229 A260246

Adjacent sequences: A124725 A124726 A124727 * A124729 A124730 A124731

KEYWORD

nonn

AUTHOR

Zak Seidov, Nov 05 2006

STATUS

approved