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A011887 [ n(n-1)(n-2)/5 ]. 1
0, 0, 0, 1, 4, 12, 24, 42, 67, 100, 144, 198, 264, 343, 436, 546, 672, 816, 979, 1162, 1368, 1596, 1848, 2125, 2428, 2760, 3120, 3510, 3931, 4384, 4872, 5394, 5952, 6547, 7180, 7854, 8568, 9324, 10123, 10966 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

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

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^3*(1+x+3*x^2-x^3+2*x^4) / ( (-1+x)^4*(1+x+x^2+x^3+x^4) ). [From R. J. Mathar, Apr 15 2010]

MATHEMATICA

CoefficientList[Series[x^3*(1+x+3*x^2-x^3+2*x^4)/((-1+x)^4*(1+x+x^2+x^3+x^4)), {x, 0, 50}], x] (* Vincenzo Librandi, Jul 07 2012 *)

PROG

(MAGMA) [Floor(n*(n-1)*(n-2)/5): n in [0..50]]; // Vincenzo Librandi, Jul 07 2012

CROSSREFS

Sequence in context: A057308 A301006 A008158 * A301164 A057305 A301211

Adjacent sequences:  A011884 A011885 A011886 * A011888 A011889 A011890

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified February 29 05:25 EST 2020. Contains 332353 sequences. (Running on oeis4.)