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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A060777 Larger central (or median) divisor of n!. 8
1, 2, 3, 6, 12, 30, 72, 210, 630, 1920, 6336, 22176, 78975, 295680, 1144000, 4576000, 18869760, 80061696, 348986880, 1560176640, 7148445696, 33530112000, 160813154304, 787718131200, 3938590656000, 20083261440000, 104351051284480, 552173794099200, 2973519499493376, 16286922357866496, 90680032493568000, 512971179263262720 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The integer part of square root of n! (A055226(n)) is situated between this d and its complementary divisor.

Essentially the same as A061056. - Nathaniel Johnston, Jun 25 2011

LINKS

Table of n, a(n) for n=1..32.

EXAMPLE

Divisors of 6!=720 are {1, 2, 3, 4, 5, 6, ..., 24, 30, ..., 360, 720}. a(6)=30, the 16th one from the 30 divisors of 720.

MATHEMATICA

Table[ Part[ Divisors[ w! ], 1+Floor[ DivisorSigma[ 0, n! ]/2 ] ], {w, a, b} ]

CROSSREFS

Cf. A027423, A055226, A000196, A000142, A000005.

Sequence in context: A261230 A014278 A061056 * A200744 A089430 A213242

Adjacent sequences:  A060774 A060775 A060776 * A060778 A060779 A060780

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 26 2001

EXTENSIONS

More terms from Don Reble, Dec 13 2001

Term a(1)=1 removed by Nathaniel Johnston, Jun 25 2011

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 November 17 08:39 EST 2019. Contains 329217 sequences. (Running on oeis4.)