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A016946 (6n+3)^2. 2
9, 81, 225, 441, 729, 1089, 1521, 2025, 2601, 3249, 3969, 4761, 5625, 6561, 7569, 8649, 9801, 11025, 12321, 13689, 15129, 16641, 18225, 19881, 21609, 23409, 25281, 27225, 29241, 31329, 33489, 35721, 38025, 40401, 42849, 45369, 47961, 50625, 53361, 56169 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

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

FORMULA

a(n) = 36*A002378(n)+9. - Jean-Bernard Fran├žois, Oct 12 2014

G.f.: 9*(1+6*x+x^2)/(1-x)^3; a(n) = 3*a(n-1)-3*a(n-2)+a(n-3); A016945(n)^2 = A000290(A016945(n)). - Wesley Ivan Hurt, Oct 13 2014

MAPLE

A016946:=n->(6*n+3)^2: seq(A016946(n), n=0..50); # Wesley Ivan Hurt, Oct 13 2014

MATHEMATICA

(6 Range[0, 50] + 3)^2 (* or *)

CoefficientList[Series[9 (1 + 6 x + x^2)/(1 - x)^3, {x, 0, 50}], x] (* Wesley Ivan Hurt, Oct 13 2014 *)

LinearRecurrence[{3, -3, 1}, {9, 81, 225}, 40] (* Harvey P. Dale, Jul 13 2015 *)

PROG

(MAGMA) [(6*n+3)^2: n in [0..60]]; // Vincenzo Librandi, May 05 2011

CROSSREFS

Cf. A000290, A002378, A016945.

Sequence in context: A207881 A207565 A207758 * A144938 A208114 A208119

Adjacent sequences:  A016943 A016944 A016945 * A016947 A016948 A016949

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified December 9 23:16 EST 2016. Contains 278993 sequences.