login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056627 Square root of largest unitary square divisor of n!. 0
1, 1, 1, 1, 1, 12, 12, 12, 36, 720, 720, 480, 480, 1680, 3024, 12096, 12096, 145152, 145152, 7257600, 345600, 1900800, 1900800, 136857600, 684288000, 4447872000, 4447872000, 435891456000, 435891456000, 3138418483200, 3138418483200, 6276836966400, 190207180800 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

Unitary analog of A055772.

LINKS

Table of n, a(n) for n=1..33.

FORMULA

a(n) = A055772(n)/A055230(n) = A000188(n!)/A055229(n!).

a(n) = A056622(n!). - Michel Marcus, Aug 16 2020

EXAMPLE

n=12, 12!=1440*1440*231, square root of the largest square divisor is 1440, but it becomes unitary if divided by g=3, so a(12)=480.

PROG

(PARI)

A055229(n) = { my(c=core(n)); gcd(c, n/c); }; \\ Charles R Greathouse IV, Nov 20 2012

A008833(n) = n/core(n) \\ Michael B. Porter, Oct 17 2009

A056623(n) = (A008833(n)/(A055229(n)^2)); \\ Antti Karttunen, Nov 19 2017

a(n) = sqrtint(A056623(n!)); \\ Michel Marcus, Aug 16 2020

CROSSREFS

Cf. A055772, A055230, A000188, A055229, A056622.

Sequence in context: A334245 A134324 A268914 * A334620 A061074 A064161

Adjacent sequences:  A056624 A056625 A056626 * A056628 A056629 A056630

KEYWORD

nonn

AUTHOR

Labos Elemer, Aug 08 2000

EXTENSIONS

More terms from Michel Marcus, Aug 16 2020

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 01:39 EDT 2021. Contains 348065 sequences. (Running on oeis4.)