A162607 a(n) = n*(n^2 - 4*n + 5)/2.

0, 1, 1, 3, 10, 25, 51, 91, 148, 225, 325, 451, 606, 793, 1015, 1275, 1576, 1921, 2313, 2755, 3250, 3801, 4411, 5083, 5820, 6625, 7501, 8451, 9478, 10585, 11775, 13051, 14416, 15873, 17425, 19075, 20826, 22681, 24643, 26715, 28900, 31201, 33621

Offset

0,4

Comments

Positive values are the row sums of triangle A159798.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Amit Kumar Singh, Akash Kumar and Thambipillai Srikanthan, Accelerating Throughput-aware Run-time Mapping for Heterogeneous MPSoCs, ACM Transactions on Design Automation of Electronic Systems, 2012. - From N. J. A. Sloane, Dec 25 2012

Index to sequences related to polygonal numbers

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

Formula

G.f.: x*(1 - 3*x + 5*x^2)/(1 - x)^4. - Vincenzo Librandi, Dec 19 2012

a(n) = A057145(n-1,n) = A072277(n-1). - R. J. Mathar, Jul 28 2016

E.g.f.: x*(x^2 - x + 2)*exp(x)/2. - G. C. Greubel, Apr 21 2018

Mathematica

f[n_]:=(n^3-n^2)/2+1; Table[f[n], {n, -1, 5!}] (* Vladimir Joseph Stephan Orlovsky, Feb 07 2010 *)
CoefficientList[Series[x*(1 - 3*x + 5*x^2)/(1 - x)^4, {x, 0, 50}], x] (* Vincenzo Librandi, Dec 19 2012 *)

Prog

(Magma) [n*(n^2 - 4*n + 5)/2: n in [0..50]]; // Vincenzo Librandi, Dec 19 2012
(PARI) for(n=0, 50, print1(n*(n^2-4*n+5)/2, ", ")) \\ G. C. Greubel, Apr 21 2018

Crossrefs

Cf. A159798.

Sequence in context: A168062 A176952 A212068 * A267574 A047667 A192963

Adjacent sequences: A162604 A162605 A162606 * A162608 A162609 A162610

Keyword

nonn,easy

Author

R. J. Mathar and Omar E. Pol, Jul 21 2009

Status

approved