The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A227765 First n-fold perfect number divided by 6, or 0 if the quotient is not an integer. 6

%I

%S 0,1,20,5040,2363739840,25724259347628441600,

%T 23551816324573058043308233789747587210723924136427520000

%N First n-fold perfect number divided by 6, or 0 if the quotient is not an integer.

%C The first n-fold perfect numbers are A007539(n) = 1, 6, 120, 30240, 14182439040, ..., for n = 1, 2, 3, 4, 5, ...

%C The first n-fold perfect numbers divided by 120 is A227766.

%C The first n-fold perfect numbers divided by 30240 is A227767.

%C The first n-fold perfect numbers divided by 14182439040 is A227768.

%C For additional comments, references, links, and cross-refs, see A007539.

%H T. D. Noe, <a href="/A227765/b227765.txt">Table of n, a(n) for n = 1..8</a>

%H E. W. Weisstein's MathWorld, <a href="http://mathworld.wolfram.com/MultiperfectNumber.html">Multiperfect Number</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Multiply_perfect_number">Multiply perfect number</a>

%F a(n) = A007539(n)/6 if 2 <= n <= 8.

%e The first 3-fold perfect number is A007539(3) = 120, so a(3) = 120/6 = 20.

%Y Cf. A007539, A227766, A227767, A227768, A227769.

%K nonn

%O 1,3

%A _Jonathan Sondow_, Jul 29 2013

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.

Last modified June 24 05:09 EDT 2021. Contains 345416 sequences. (Running on oeis4.)