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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130065 (n / GreatestPrimeFactor(n)) * SmallestPrimeFactor(n). 7
1, 2, 3, 4, 5, 4, 7, 8, 9, 4, 11, 8, 13, 4, 9, 16, 17, 12, 19, 8, 9, 4, 23, 16, 25, 4, 27, 8, 29, 12, 31, 32, 9, 4, 25, 24, 37, 4, 9, 16, 41, 12, 43, 8, 27, 4, 47, 32, 49, 20, 9, 8, 53, 36, 25, 16, 9, 4, 59, 24, 61, 4, 27, 64, 25, 12, 67, 8, 9, 20, 71, 48, 73, 4, 45, 8, 49, 12, 79, 32, 81 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = n*A020639(n)/A006530(n) = A052126(n)*A020639(n);

a(n)<=n; a(n)=n iff n is a prime power: a(A000961(n))=A000961(n);

a(A001221(n)) <= A001221(n); a(A001222(n)) = A001222(n);

a(n) = A130064(n)-n*A046665(n)*A074320(n)/A066048(n) = A000290(n)/A130064(n).

LINKS

R. Zumkeller, Table of n, a(n) for n = 1..10000

CROSSREFS

Sequence in context: A119816 A227538 A068794 * A079881 A058084 A074882

Adjacent sequences:  A130062 A130063 A130064 * A130066 A130067 A130068

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 05 2007

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 9 17:46 EST 2016. Contains 278985 sequences.