A026040 a(n) = dot_product(1,2,...,n)*(4,5,...,n,1,2,3).

24, 40, 64, 98, 144, 204, 280, 374, 488, 624, 784, 970, 1184, 1428, 1704, 2014, 2360, 2744, 3168, 3634, 4144, 4700, 5304, 5958, 6664, 7424, 8240, 9114, 10048, 11044, 12104, 13230, 14424, 15688, 17024, 18434, 19920, 21484, 23128, 24854, 26664

Offset

4,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 4..1000

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

a(n) = n(n^2 - 3n + 14)/3 (n >= 4). - Emeric Deutsch, Nov 27 2006

G.f.: x^4*(24 - 56*x + 48*x^2 - 14*x^3)/(1 - x)^4. - Colin Barker, Sep 17 2012

Maple

a:=n->n*(n^2-3*n+14)/3: seq(a(n), n=4..50); # Emeric Deutsch, Nov 27 2006

Mathematica

Table[Range[n].RotateLeft[Range[n], 3], {n, 4, 52}] (* T. D. Noe, Nov 07 2006 *)
CoefficientList[Series[(24 - 56 x + 48 x^2 - 14 x^3)/(1 - x)^4, {x, 0, 50}], x] (* Vincenzo Librandi, Oct 17 2013 *)

Prog

(Magma) [n*(n^2-3*n+14)/3: n in [4..50]]; // Vincenzo Librandi, Oct 17 2013

Crossrefs

Column 3 of triangle A094414.

Sequence in context: A294029 A366675 A195562 * A259217 A211567 A316271

Adjacent sequences: A026037 A026038 A026039 * A026041 A026042 A026043

Keyword

nonn,easy

Author

Clark Kimberling

Extensions

Corrected by T. D. Noe, Nov 07 2006

Status

approved