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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A047928 a(n) = n*(n-1)^2*(n-2). 13
0, 12, 72, 240, 600, 1260, 2352, 4032, 6480, 9900, 14520, 20592, 28392, 38220, 50400, 65280, 83232, 104652, 129960, 159600, 194040, 233772, 279312, 331200, 390000, 456300, 530712, 613872, 706440, 809100, 922560, 1047552, 1184832 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 2..1000

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

FORMULA

a(n) = A002378(n)*A002378(n+1). - Zerinvary Lajos, Apr 11 2006

a(n) = 12*A002415(n+1) = 2*A083374(n) = 4*A006011(n+1) = 6*A008911(n+1). - Zerinvary Lajos, May 09 2007

a(n) = floor((n-1)^6/((n-1)^2+1)). - Gary Detlefs, Feb 11 2010

MAPLE

seq(floor(n^6/(n^2+1)), n=1..25); # Gary Detlefs, Feb 11 2010

MATHEMATICA

f[n_]:=n*(n-1)^2*(n-2); f[Range[2, 60]] (* Vladimir Joseph Stephan Orlovsky, Feb 10 2011 *)

PROG

(MAGMA) [ n*(n-1)^2*(n-2): n in [2..40]]; // Vincenzo Librandi, May 02 2011

(PARI) a(n)=n^4 - 4*n^3 + 5*n^2 - 2*n \\ Charles R Greathouse IV, May 02, 2011

CROSSREFS

Cf. A002378, A002415, A006011, A008911, A083374.

Sequence in context: A304164 A199531 A188660 * A300847 A235870 A008533

Adjacent sequences:  A047925 A047926 A047927 * A047929 A047930 A047931

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

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 August 20 07:48 EDT 2019. Contains 326143 sequences. (Running on oeis4.)