A124729 -id:A124729 - cp's OEIS frontend

A124728 Numbers k such that k, k+1, k+2 and k+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

Offset: 1

Zak Seidov, Nov 05 2006

nonn

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

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

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

Cf. A045940, A124057, A124729.

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

A267361 Numbers n such that 6 consecutive numbers starting with n are products of 5 primes.

Original entry on oeis.org

14845324, 22515700, 22721584, 25693260, 28387952, 28837625, 39664372, 41268874, 45595624, 46631220, 47484279, 50845288, 61818774, 63618020, 65411124, 69358372, 69921004, 69921005, 70195563, 76845965

Offset: 1

Zak Seidov, Jan 25 2016

nonn

a(1)=14845324=A067820(6).

Subsequence of A124729. Cf. A067820.

A267362 Numbers n such that 5 consecutive numbers starting with n are products of 5 primes.

Original entry on oeis.org

632148, 1380246, 3322374, 3755672, 4294374, 4336548, 4546071, 5491574, 5924148, 6033752, 6884268, 6943472, 8179566, 8223368, 8252628, 8284548, 8544470, 8646504, 8923472, 8928774, 8961325, 9084392

Offset: 1

Zak Seidov, Jan 20 2016

nonn

Both n-1 and n+5 may or not be products of 5 primes.
a(1)=632148=A067820(5).
First number n such that also n+5 is product of 5 primes is a(50)=14845324=A067820(6).

			632148=2*2*3*11*4789, 632149=7*7*7*19*97, 632150=2*5*5*47*269,
632151=3*3*3*13*1801, 632152=2*2*2*31*2549.

Zak Seidov, Table of n, a(n) for n = 1..70

Subsequence of A124729. Cf. A067820, A267361.

SequencePosition[PrimeOmega[Range[91*10^5]],{5,5,5,5,5}][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 05 2017 *)

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A124728 Numbers k such that k, k+1, k+2 and k+3 are products of 4 primes.

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A267361 Numbers n such that 6 consecutive numbers starting with n are products of 5 primes.

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A267362 Numbers n such that 5 consecutive numbers starting with n are products of 5 primes.

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Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica