This site is supported by donations to The OEIS Foundation.



Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A079390 spf(n) * spf(n+1) * spf(n+2), where spf=A020639 (smallest prime factor). 1


%S 6,12,30,20,70,28,42,12,66,44,286,52,78,12,102,68,646,76,114,12,138,

%T 92,230,20,30,12,174,116,1798,124,186,12,30,20,370,148,222,12,246,164,

%U 3526,172,258,12,282,188,658,28,42,12,318,212,530,20,30,12,354,236,7198,244

%N spf(n) * spf(n+1) * spf(n+2), where spf=A020639 (smallest prime factor).

%C For n>2, a(n) is a record value iff (n,n+2) is a twin prime pair (conjecture).

%H Harvey P. Dale, <a href="/A079390/b079390.txt">Table of n, a(n) for n = 1..1000</a>

%t Times@@@Partition[Table[FactorInteger[n][[1,1]],{n,70}],3,1] (* _Harvey P. Dale_, Oct 06 2015 *)

%Y Cf. A001359, A006512, A014574.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Feb 20 2003

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 January 16 23:44 EST 2019. Contains 319206 sequences. (Running on oeis4.)