login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A157486 Numbers n such that n-+1 are divisible by exactly 6 primes, counted with multiplicity. 3
1889, 3079, 4591, 5023, 6175, 6641, 7649, 9881, 10961, 11501, 11935, 12689, 13751, 14417, 15499, 15713, 16687, 18017, 18089, 18271, 19169, 19249, 19889, 19951 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..4000

MATHEMATICA

q=6; lst={}; Do[If[Plus@@Last/@FactorInteger[n-1]==q&&Plus@@Last/@FactorInteger[n+1]==q, AppendTo[lst, n]], {n, 9!}]; lst

Mean/@SequencePosition[PrimeOmega[Range[20000]], {6, _, 6}] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 23 2019 *)

CROSSREFS

Cf. A124936, A014612, A157483, A157484, A157485

Sequence in context: A237540 A206746 A106764 * A086476 A279621 A168226

Adjacent sequences: A157483 A157484 A157485 * A157487 A157488 A157489

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Mar 01 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 1 14:52 EST 2022. Contains 358468 sequences. (Running on oeis4.)