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

Author

Clark Kimberling

Keywords

• nonn
• easy

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).

Crossrefs

Column 3 of triangle A094414.

Programs

Magma

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

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 *)
LinearRecurrence[{4,-6,4,-1},{24,40,64,98},60] (* Harvey P. Dale, Nov 04 2024 *)

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

Extensions

Corrected by T. D. Noe, Nov 07 2006