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a(n) = (8*n + 5)^2.
3

%I #24 Oct 28 2023 11:32:34

%S 25,169,441,841,1369,2025,2809,3721,4761,5929,7225,8649,10201,11881,

%T 13689,15625,17689,19881,22201,24649,27225,29929,32761,35721,38809,

%U 42025,45369,48841,52441,56169,60025,64009,68121,72361,76729,81225,85849,90601,95481,100489,105625

%N a(n) = (8*n + 5)^2.

%H Vincenzo Librandi, <a href="/A017126/b017126.txt">Table of n, a(n) for n = 0..10000</a>

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

%F G.f.: ( -25 - 94*x - 9*x^2 ) / (x-1)^3. - _R. J. Mathar_, May 08 2015

%F E.g.f.: exp(x)*(25 + 144*x + 64*x^2). - _Stefano Spezia_, Oct 28 2023

%t (8Range[0,40]+5)^2 (* _Harvey P. Dale_, Mar 12 2011 *)

%o (Magma) [(8*n+5)^2: n in [0..35] ]; // _Vincenzo Librandi_, Jul 21 2011

%o (PARI) a(n)=(8*n+5)^2 \\ _Charles R Greathouse IV_, Jun 17 2017

%Y Cf. A004770.

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_