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 A387476 #14 Aug 31 2025 15:48:20
%S A387476 1,0,2,2,4,16,12,72,88,264,608,1056,3280,5504,15328,31904,71104,
%T A387476 175488,358080,900736,1925248,4518016,10404864,23138304,54970624,
%U A387476 122038272,286077440,651510272,1492685824,3465687040,7876488192,18322630656,41904609280,96788580352,223335882752
%N A387476 a(n) = Sum_{k=0..floor(n/2)} 2^k * binomial(k,n-2*k)^2.
%H A387476 Vincenzo Librandi, <a href="/A387476/b387476.txt">Table of n, a(n) for n = 0..2000</a>
%F A387476 G.f.: 1/sqrt((1-2*x^2-2*x^3)^2 - 16*x^5).
%t A387476 Table[Sum[2^k* Binomial[k,n-2*k]^2,{k,0,Floor[n/2]}],{n,0,40}] (* _Vincenzo Librandi_, Aug 31 2025 *)
%o A387476 (PARI) a(n) = sum(k=0, n\2, 2^k*binomial(k, n-2*k)^2);
%o A387476 (Magma) [(&+[2^k * Binomial(k,n-2*k)^2: k in [0..Floor(n/2)]]): n in [0..40]]; // _Vincenzo Librandi_, Aug 31 2025
%Y A387476 Cf. A375276, A387477.
%Y A387476 Cf. A052907.
%K A387476 nonn,new
%O A387476 0,3
%A A387476 _Seiichi Manyama_, Aug 30 2025