A026066 dot_product(n,n-1,...2,1)*(7,8,...,n,1,2,3,4,5,6).

105, 168, 246, 340, 451, 580, 728, 896, 1085, 1296, 1530, 1788, 2071, 2380, 2716, 3080, 3473, 3896, 4350, 4836, 5355, 5908, 6496, 7120, 7781, 8480, 9218, 9996, 10815, 11676, 12580, 13528, 14521, 15560, 16646, 17780, 18963, 20196, 21480, 22816, 24205, 25648, 27146, 28700, 30311

Offset

7,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 7..1000

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

Formula

a(n) = (1/6) * (n^2 + 21n - 106) * n. - Ralf Stephan, Apr 05 2004

G.f.: x^7*(105-252*x+204*x^2-56*x^3)/(1-x)^4. - Colin Barker, Sep 17 2012

Mathematica

CoefficientList[Series[(105 - 252 x + 204 x^2 - 56 x^3)/(1 - x)^4, {x, 0, 60}], x] (* Vincenzo Librandi, Oct 17 2013 *)
Table[Range[n, 1, -1].Join[Range[7, n], Range[6]], {n, 7, 60}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {105, 168, 246, 340}, 50] (* Harvey P. Dale, Dec 04 2024 *)

Prog

(Magma) [n*(n^2+21*n-106)/6: n in [7..60]]; // Vincenzo Librandi, Oct 17 2013

Crossrefs

Column 6 of triangle A094415.

Sequence in context: A128284 A161962 A046887 * A167629 A326141 A347881

Adjacent sequences: A026063 A026064 A026065 * A026067 A026068 A026069

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved