A162259 a(n) = (2*n^3 + 5*n^2 - 17*n)/2.

-5, 1, 24, 70, 145, 255, 406, 604, 855, 1165, 1540, 1986, 2509, 3115, 3810, 4600, 5491, 6489, 7600, 8830, 10185, 11671, 13294, 15060, 16975, 19045, 21276, 23674, 26245, 28995, 31930, 35056, 38379, 41905, 45640, 49590, 53761, 58159, 62790, 67660

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. A155551.

Programs

Mathematica

CoefficientList[Series[(-5+21*x-10*x^2)/(1-x)^4,{x,0,40}],x] (* or *) LinearRecurrence[{4, -6, 4, -1}, {-5, 1, 24, 70}, 50] (* Vincenzo Librandi, Mar 04 2012 *)
Table[(2n^3+5n^2-17n)/2,{n,40}] (* Harvey P. Dale, May 10 2021 *)

Formula

Row sums from A155551: a(n) = Sum_{m=1..n} (2*m*n + m + n - 9).

From Vincenzo Librandi, Mar 04 2012: (Start)

G.f.: x*(-5 + 21*x - 10*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 04 2012