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A153796 6 times octagonal numbers: a(n) = 6*n*(3*n-2). 4
0, 6, 48, 126, 240, 390, 576, 798, 1056, 1350, 1680, 2046, 2448, 2886, 3360, 3870, 4416, 4998, 5616, 6270, 6960, 7686, 8448, 9246, 10080, 10950, 11856, 12798, 13776, 14790, 15840, 16926, 18048, 19206, 20400, 21630, 22896, 24198, 25536, 26910, 28320, 29766 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

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

FORMULA

a(n) = 18*n^2 - 12*n = 6*A000567(n) = 3*A139267(n) = 2*A152751(n).

a(n) = a(n-1) + 36*n - 30 (with a(0)=0). - Vincenzo Librandi, Dec 15 2010

From G. C. Greubel, Aug 29 2016: (Start)

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2.

G.f.: 6*x*(1 + 5*x)/(1 - x)^3.

E.g.f.: 6*x*(1 + 3*x)*exp(x). (End)

MAPLE

A153796:=n->6*n*(3*n-2): seq(A153796(n), n=0..60); # Wesley Ivan Hurt, Aug 29 2016

MATHEMATICA

s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 6, 8!, 36}]; lst (* Vladimir Joseph Stephan Orlovsky, Apr 03 2009 *)

Table[6*n*(3*n-2), {n, 0, 25}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 6, 48}, 25] (* G. C. Greubel, Aug 29 2016 *)

PROG

(MAGMA) [6*n*(3*n-2): n in [0..60]]; // Wesley Ivan Hurt, Aug 29 2016

(PARI) a(n)=6*n*(3*n-2) \\ Charles R Greathouse IV, Aug 29 2016

CROSSREFS

Cf. A000567, A139267, A152751.

Sequence in context: A274131 A259121 A052651 * A250226 A250274 A167547

Adjacent sequences:  A153793 A153794 A153795 * A153797 A153798 A153799

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Jan 19 2009

STATUS

approved

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Last modified February 19 22:04 EST 2020. Contains 332060 sequences. (Running on oeis4.)