login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242621 Start of the least triple of consecutive squarefree numbers each of which has exactly n distinct prime factors. 8
2, 33, 1309, 27962, 3323705, 296602730, 41704979953 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

As the example of a(4)=27962 shows, "consecutive squarefree numbers" means consecutive elements of A005117, not necessarily consecutive integers that (additionally) are squarefree; this would be a more restrictive condition.

a(8) <= 102099792179229 because A093550 - 1 is an upper bound of the present sequence.

LINKS

Table of n, a(n) for n=1..7.

Daniel C. Mayer, Define an "m-triple" to consist of three consecutive squarefree positive integers, each with exactly m prime divisors, Number Theory group on LinkedIn.com

EXAMPLE

The two squarefree numbers following a(4)=27962, namely, 27965 and 27966, also have 4 prime divisors just as a(4).

CROSSREFS

See A242605-A242608 for triples of consecutive squarefree numbers with m=2,..,5 prime factors.

See A246470 for the quadruplet and A246548 for the quintuplet versions of this sequence.

See A039833, A066509, A176167 and A192203 for triples of consecutive numbers which are squarefree and have m=2,..,5 prime factors.

Sequence in context: A256278 A204239 A198901 * A206385 A263052 A090335

Adjacent sequences:  A242618 A242619 A242620 * A242622 A242623 A242624

KEYWORD

nonn

AUTHOR

M. F. Hasler, May 18 2014

EXTENSIONS

Edited and a(6)-a(7) added by Hans Havermann, Aug 27 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 20 05:25 EDT 2019. Contains 326139 sequences. (Running on oeis4.)