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 A033574 a(n) = (2*n+1)*(10*n+1). 2

%I

%S 1,33,105,217,369,561,793,1065,1377,1729,2121,2553,3025,3537,4089,

%T 4681,5313,5985,6697,7449,8241,9073,9945,10857,11809,12801,13833,

%U 14905,16017,17169,18361,19593,20865,22177,23529,24921,26353,27825,29337,30889,32481,34113,35785,37497,39249

%N a(n) = (2*n+1)*(10*n+1).

%H G. C. Greubel, <a href="/A033574/b033574.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).

%F From _G. C. Greubel_, Oct 12 2019: (Start)

%F G.f.: (1 + 30*x + 9*x^2)/(1-x)^3.

%F E.g.f.: (1 + 32*x + 20*x^2)*exp(x). (End)

%p seq((2*n+1)*(10*n+1), n=0..50); # _G. C. Greubel_, Oct 12 2019

%t Table[(2*n+1)*(10*n+1), {n, 0, 50}] (* _G. C. Greubel_, Oct 12 2019 *)

%o (PARI) a(n)=(2*n+1)*(10*n+1) \\ _Charles R Greathouse IV_, Jun 17 2017

%o (MAGMA) [(2*n+1)*(10*n+1): n in [0..50]] # _G. C. Greubel_, Oct 12 2019

%o (Sage) [(2*n+1)*(10*n+1) for n in range(50)] # _G. C. Greubel_, Oct 12 2019

%o (GAP) List([0..50], n-> (2*n+1)*(10*n+1)); # _G. C. Greubel_, Oct 12 2019

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_

%E Terms a(33) onward added by _G. C. Greubel_, Oct 12 2019

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Last modified October 21 02:29 EDT 2021. Contains 348141 sequences. (Running on oeis4.)