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A162607 a(n) = n*(n^2 - 4*n + 5)/2. 5
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Positive values are the row sums of triangle A159798.

The formula and the first positive terms of this sequence is mentioned in the comment lines in the entry 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

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Last modified June 13 17:14 EDT 2021. Contains 345008 sequences. (Running on oeis4.)