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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A254787 a(n)= least initial term of n consecutive primes {p(m),..,p(m+n-1)} such that all numbers {1+p(m),..,1+p(m+n-1)} are a product of the same number k primes, where p(m) is m-th prime A000040(m). 1
2, 3, 139, 557, 3821, 53609, 179659, 7190917, 3599100, 16687573, 20394197, 101439558 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Corresponding values of m are: 1,2,34,102,530,5462,16309,488739,3599100,308495917,20394197,101439558

Corresponding values of k are: 1,2,4,4,5,4,5,4,5,4,5,5

A023514(i=m,..,m+n-1) are of the same value.

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

a(2)=3, because {p(2),p(3)}={3,5}, and {4,6}={2^2,2*3}, k=2;

a(3)=139, because {p(34),p(35),p(36)}={139,149,151}, and {140,150,152}={2^2*5*7,2*3*5^2,2^3*19}, k=4.

CROSSREFS

Cf. A000040, A023514.

Sequence in context: A066908 A057738 A234999 * A042073 A124236 A115231

Adjacent sequences:  A254784 A254785 A254786 * A254788 A254789 A254790

KEYWORD

nonn

AUTHOR

Zak Seidov, Feb 15 2015

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 December 10 23:33 EST 2018. Contains 318049 sequences. (Running on oeis4.)