A162262 a(n) = (2*n^3 + 5*n^2 - 13*n)/2.

-3, 5, 30, 78, 155, 267, 420, 620, 873, 1185, 1562, 2010, 2535, 3143, 3840, 4632, 5525, 6525, 7638, 8870, 10227, 11715, 13340, 15108, 17025, 19097, 21330, 23730, 26303, 29055, 31992, 35120, 38445, 41973, 45710, 49662, 53835, 58235, 62868, 67740

Offset: 1

Author

Vincenzo Librandi, Jun 29 2009

Keywords

• sign
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Crossrefs

Cf. A144670.

Programs

Mathematica

LinearRecurrence[{4, -6, 4, -1}, {-3, 5, 30, 78}, 50] (* or *) CoefficientList[Series[(-3+17*x-8*x^2)/(1-x)^4,{x,0,50}],x] (* Vincenzo Librandi, Mar 04 2012 *)
Table[(2n^3+5n^2-13n)/2,{n,60}] (* Harvey P. Dale, Jul 03 2023 *)

Formula

Row sums from A144670: a(n) = Sum_{m=1..n} (2*m*n + m + n - 7).

From Vincenzo Librandi, Mar 05 2012: (Start)

G.f.: x*(-3 + 17*x - 8*x^2)/(1-x)^4.

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End)

Extensions

New name from Vincenzo Librandi, Mar 05 2012