A162260 a(n) = (n^3 + 4*n^2 - n)/2.

2, 11, 30, 62, 110, 177, 266, 380, 522, 695, 902, 1146, 1430, 1757, 2130, 2552, 3026, 3555, 4142, 4790, 5502, 6281, 7130, 8052, 9050, 10127, 11286, 12530, 13862, 15285, 16802, 18416, 20130, 21947, 23870, 25902, 28046, 30305, 32682, 35180, 37802

Offset

1,1

Comments

Row 2 of the convolution array A213771. - Clark Kimberling, Jul 04 2012

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).

Formula

Row sums from A154614: a(n) = Sum_{m=1..n} (m*n + m + n - 1).

From Vincenzo Librandi, Mar 05 2012: (Start)

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

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

Mathematica

CoefficientList[Series[(2+3*x-2*x^2)/(1-x)^4, {x, 0, 40}], x] (* or *) LinearRecurrence[{4, -6, 4, -1}, {2, 11, 30, 62}, 50] (* Vincenzo Librandi, Mar 05 2012 *)
Table[(n^3+4 n^2-n)/2, {n, 50}] (* Harvey P. Dale, Jul 05 2020 *)

Crossrefs

Cf. A154614.

Sequence in context: A178629 A062802 A103830 * A023664 A023622 A119438

Adjacent sequences: A162257 A162258 A162259 * A162261 A162262 A162263

Keyword

nonn,easy

Author

Vincenzo Librandi, Jun 29 2009

Extensions

New name from Vincenzo Librandi, Mar 05 2012

Status

approved