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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A011897 a(n) = floor(n*(n-1)*(n-2)/15). 1
0, 0, 0, 0, 1, 4, 8, 14, 22, 33, 48, 66, 88, 114, 145, 182, 224, 272, 326, 387, 456, 532, 616, 708, 809, 920, 1040, 1170, 1310, 1461, 1624, 1798, 1984, 2182, 2393, 2618, 2856, 3108, 3374, 3655, 3952, 4264, 4592 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,1,-3,3,-1). [From R. J. Mathar, Apr 15 2010]

FORMULA

From R. J. Mathar, Apr 15 2010:

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-5) - 3*a(n-6) + 3*a(n-7) - a(n-8).

G.f.: x^4*(x^3-x^2+x+1) / ( (-1+x)^4*(x^4+x^3+x^2+x+1) ). (End)

MATHEMATICA

CoefficientList[Series[x^4(x^3-x^2+x+1)/((-1+x)^4(x^4+x^3+x^2+x+1)), {x, 0, 45}], x]  (* Harvey P. Dale, Feb 25 2011 *)

PROG

(MAGMA) [Floor(n*(n-1)*(n-2)/15): n in [0..50]]; // Vincenzo Librandi, Jul 07 2012

CROSSREFS

Sequence in context: A054347 A194149 A003682 * A110895 A049628 A063757

Adjacent sequences:  A011894 A011895 A011896 * A011898 A011899 A011900

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 October 17 08:36 EDT 2019. Contains 328107 sequences. (Running on oeis4.)