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 A171552 #10 May 10 2024 16:51:45 %S A171552 1,2,0,-8,-16,-64,-192,-384,-1024,-2560,-5120,-12288,-28672,-57344, %T A171552 -131072,-294912,-589824,-1310720,-2883584,-5767168,-12582912, %U A171552 -27262976,-54525952,-117440512,-251658240,-503316480,-1073741824,-2281701376 %N A171552 a(n) = 2^n*floor((5-2n)/3). %C A171552 Hankel transform of A131428. %H A171552 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,8,-16). %F A171552 G.f.: (1-4x^2-16x^3)/((1-2x)(1-8x^3)). %Y A171552 Cf. A131428. %K A171552 easy,sign %O A171552 0,2 %A A171552 _Paul Barry_, Dec 11 2009