This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A114619 #23 Mar 15 2024 23:20:32 %S A114619 0,2,8,50,288,1682,9800,57122,332928,1940450,11309768,65918162, %T A114619 384199200,2239277042,13051463048,76069501250,443365544448, %U A114619 2584123765442,15061377048200,87784138523762,511643454094368 %N A114619 a(n) = 2*A079291(n) (twice squares of Pell numbers). %H A114619 G. C. Greubel, <a href="/A114619/b114619.txt">Table of n, a(n) for n = 0..1000</a> %H A114619 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (5,5,-1). %F A114619 a(n) = 2*A000129(n)^2. %F A114619 G.f.: 2*x*(1-x)/((1+x)*(1-6*x+x^2)). %F A114619 a(n) = A001333(n)^2 - (-1)^n. - Antonio Pane (apane1(AT)spc.edu), Dec 15 2007 %t A114619 2*Fibonacci[Range[0, 30], 2]^2 (* _G. C. Greubel_, Aug 18 2022 *) %o A114619 (Magma) [n le 3 select 2*(n-1)^2 else 5*Self(n-1) +5*Self(n-2) -Self(n-3): n in [1..31]]; // _G. C. Greubel_, Aug 18 2022 %o A114619 (SageMath) [2*lucas_number1(n,2,-1)^2 for n in (0..30)] # _G. C. Greubel_, Aug 18 2022 %Y A114619 Cf. A000129, A001109, A001333, A001542, A079291. %Y A114619 Cf. also A090390, A108475, A114619, A116484. %K A114619 easy,nonn %O A114619 0,2 %A A114619 _Creighton Dement_, Feb 17 2006 %E A114619 Entry revised by _N. J. A. Sloane_, Mar 15 2024