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 A174595 #34 Sep 08 2022 08:45:51
%S A174595 0,0,1,4,4,16,9,36,16,64,25,100,36,144,49,196,64,256,81,324,100,400,
%T A174595 121,484,144,576,169,676,196,784,225,900,256,1024,289,1156,324,1296,
%U A174595 361,1444,400,1600,441,1764,484,1936,529,2116,576,2304,625,2500,676,2704,729,2916,784,3136,841,3364,900
%N A174595 a(n) = 5*n^2/8 - n + 1/2 + (-1)^n*(-3*n^2/8 + n - 1/2).
%C A174595 Based on A174571.
%H A174595 Vincenzo Librandi, <a href="/A174595/b174595.txt">Table of n, a(n) for n = 0..1000</a>
%H A174595 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,1).
%F A174595 a(n) = A029578(n)^2.
%F A174595 Interleaving of A000290 and 4*A000290.
%F A174595 G.f.: -x^2*(4*x+1)*(x^2+1) / ( (x-1)^3*(1+x)^3 ).
%F A174595 a(n) = 3*a(n-2) - 3*a(n-4) + a(n-6).
%F A174595 E.g.f.: (1/8)*exp(-x)*(- 4 - 5*x - 3*x^2 +exp(2*x)*(4 - 3*x + 5*x^2)). - _Stefano Spezia_, Nov 02 2018
%t A174595 LinearRecurrence[{0,3,0,-3,0,1},{0,0,1,4,4,16},70] (* _Harvey P. Dale_, Jun 26 2012 *)
%t A174595 CoefficientList[Series[1/8 E^-x (-4 - 5 x - 3 x^2 + E^(2 x) (4 - 3 x + 5 x^2)), {x, 0, 50}], x]*Table[k!, {k, 0, 50}] (* _Stefano Spezia_, Nov 02 2018 *)
%o A174595 (Magma) [5*n^2/8-n+1/2+(-1)^n*(-3*n^2/8+n-1/2): n in [0..60]]; // _Vincenzo Librandi_, Aug 04 2011
%o A174595 (PARI) vector(50, n, n--; (5*n^2 -8*n + 4 - (-1)^n*(3*n^2 - 8*n +4))/8) \\ _G. C. Greubel_, Nov 02 2018
%K A174595 nonn,easy
%O A174595 0,4
%A A174595 _Paul Curtz_, Nov 29 2010