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A139576 a(n) = n(2n+9). 6
0, 11, 26, 45, 68, 95, 126, 161, 200, 243, 290, 341, 396, 455, 518, 585, 656, 731, 810, 893, 980, 1071, 1166, 1265, 1368, 1475, 1586, 1701, 1820, 1943, 2070, 2201, 2336, 2475, 2618, 2765, 2916, 3071, 3230, 3393, 3560, 3731, 3906 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..42.

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

a(n) = 2*n^2 + 9*n.

a(n) = a(n-1) + 4*n + 7 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010

MATHEMATICA

s=0; lst={s}; Do[s+=n++ +11; AppendTo[lst, s], {n, 0, 7!, 4}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)

Table[Sum[(2*i + n - 1), {i, 4, n}], {n, 3, 45}] (* Zerinvary Lajos, Jul 11 2009 *)

Table[n(2n+9), {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 11, 26}, 50] (* Harvey P. Dale, Dec 18 2018 *)

PROG

(PARI) a(n)=n*(2*n+9) \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Cf. A014105, A014106, A033537, A130861, A139577, A139578, A139579, A139580, A139581.

Sequence in context: A161451 A100566 A101969 * A166137 A212018 A046806

Adjacent sequences:  A139573 A139574 A139575 * A139577 A139578 A139579

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, May 19 2008

STATUS

approved

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Last modified February 18 10:22 EST 2019. Contains 320250 sequences. (Running on oeis4.)