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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130089 a(n) = denominator of Product_{k=1..n} k^mu(n+1-k), where mu(k) = A008683(k). 3
1, 1, 2, 3, 12, 20, 45, 14, 70, 864, 525, 880, 6237, 3328, 3003, 900, 25025, 60928, 53703, 19456, 3997125, 1209600, 3556553, 30912, 67643667, 11264000, 244375, 26687232, 52055003, 2702336, 351469125, 90272000, 47453715, 1284636672 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
EXAMPLE
a(5) = denominator(1^(-1)*2^(0)*3^(-1)*4^(-1)*5^(1)) = denominator(5/12) = 12.
MAPLE
with(numtheory): a:=n->denom(mul(k^mobius(n+1-k), k=1..n)): seq(a(n), n=1..41); # Emeric Deutsch, May 09 2007
PROG
(PARI) a(n) = denominator(prod(k=1, n, k^moebius(n+1-k))); \\ Michel Marcus, Feb 12 2019
CROSSREFS
Sequence in context: A140989 A281086 A355847 * A323119 A307035 A319404
KEYWORD
frac,nonn
AUTHOR
Leroy Quet, May 06 2007
EXTENSIONS
More terms from Emeric Deutsch, May 09 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)