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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A079877 Numbers n that are divisible by at least one twin prime (A001097), and furthermore, if a twin prime p divides n, then the other twin q also divides n. 1
 15, 30, 35, 45, 60, 70, 75, 90, 105, 120, 135, 140, 143, 150, 165, 175, 180, 195, 210, 225, 240, 245, 255, 270, 280, 285, 286, 300, 315, 323, 330, 345, 350, 360, 375, 385, 390, 405, 420, 429, 435, 450, 455, 465, 480, 490, 495, 510, 525, 540, 555, 560, 570 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers that are divisible by both primes of some twin-prime pair. Harvey P. Dale, Aug 18 2017 By definition, if k is in the sequence, then so is every positive multiple of k. - Richard Locke Peterson, Aug 17 2017 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE 429 = 3*11*13 = 3*A001359(3)*A006512(3), therefore 429 is a term. MATHEMATICA Select[Range[600], MemberQ[Differences[Transpose[FactorInteger[#]][[1]]], 2]&] (* Harvey P. Dale, Sep 19 2011 *) CROSSREFS Cf. A001097, A001359, A006512, A037074, A062505, A074480, A289484. Sequence in context: A162592 A239247 A291045 * A215951 A060700 A167210 Adjacent sequences: A079874 A079875 A079876 * A079878 A079879 A079880 KEYWORD nonn AUTHOR Reinhard Zumkeller, Feb 20 2003 EXTENSIONS Definition clarified by N. J. A. Sloane, Aug 18 2017 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.

Last modified August 13 07:44 EDT 2024. Contains 375113 sequences. (Running on oeis4.)