|
|
A132998
|
|
a(n) = n^4 - n^3 - n^2.
|
|
2
|
|
|
0, -1, 4, 45, 176, 475, 1044, 2009, 3520, 5751, 8900, 13189, 18864, 26195, 35476, 47025, 61184, 78319, 98820, 123101, 151600, 184779, 223124, 267145, 317376, 374375, 438724, 511029, 591920, 682051, 782100, 892769
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
a(n) = n^4 - n^3 - n^2.
G.f.: x*(-1+9*x+15*x^2+x^3)/(1-x)^5. - R. J. Mathar, Nov 14 2007
|
|
EXAMPLE
|
a(7)=2009 because 7^4=2401, 7^3=343, 7^2=49 and we can write 2401-343-49=2009.
|
|
MAPLE
|
|
|
MATHEMATICA
|
CoefficientList[Series[- x (-1 + 9 x + 15 x^2 + x^3)/(-1 + x)^5, {x, 0, 50}], x] (* Vincenzo Librandi, May 21 2014 *)
LinearRecurrence[{5, -10, 10, -5, 1}, {0, -1, 4, 45, 176}, 50] (* G. C. Greubel, Sep 28 2017 *)
|
|
PROG
|
(PARI) x='x+O('x^50); Vec(x*(-1+9*x+15*x^2+x^3)/(1-x)^5) \\ G. C. Greubel, Sep 28 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|