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 A152594 #18 Jun 18 2025 00:52:45
%S A152594 1,-1,3,-13,59,-269,1227,-5597,25531,-116461,531243,-2423293,11053979,
%T A152594 -50423309,230008587,-1049196317,4785964411,-21831429421,99585218283,
%U A152594 -454263232573,2072145726299,-9452202166349,43116719379147
%N A152594 a(n) = -5*a(n-1)-2*a(n-2), n>1 ; a(0)=1, a(1)=-1 .
%H A152594 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (-5,-2).
%F A152594 G.f.: (1+4*x)/(1+5*x+2*x^2).
%F A152594 a(n) = Sum_{k=0..n-1} A147703(n,k)*(-2)^(n-k).
%F A152594 a(n) = (-1)^n*A052984(n-1), n>=1 ; a(0)=1.
%F A152594 E.g.f.: exp(-5*x/2)*(17*cosh(sqrt(17)*x/2) + 3*sqrt(17)*sinh(sqrt(17)*x/2))/17. - _Stefano Spezia_, Jun 17 2025
%t A152594 LinearRecurrence[{-5,-2},{1,-1},30] (* _Harvey P. Dale_, Jun 18 2015 *)
%Y A152594 Cf. A052984, A147703.
%K A152594 sign,easy
%O A152594 0,3
%A A152594 _Philippe Deléham_, Dec 09 2008