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 A115525 #14 Dec 14 2023 05:31:55
%S A115525 1,1,-2,0,1,0,-1,0,0,1,-1,-1,1,1,-2,0,1,0,-1,0,0,1,-1,-1,1,1,-2,0,1,0,
%T A115525 -1,0,0,1,-1,-1,1,1,-2,0,1,0,-1,0,0,1,-1,-1,1,1,-2,0,1,0,-1,0,0,1,-1,
%U A115525 -1,1,1,-2,0,1,0,-1,0,0,1,-1,-1
%N A115525 Periodic {1,1,-2,0,1,0,-1,0,0,1,-1,-1}.
%C A115525 Diagonal sums of number triangle A115524.
%H A115525 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-1,0,1,1,1).
%F A115525 G.f.: (1+2x-x^3-2x^4-x^5)/(1+x+x^2-x^4-x^5-x^6).
%t A115525 PadRight[{},120,{1,1,-2,0,1,0,-1,0,0,1,-1,-1}] (* _Harvey P. Dale_, Aug 20 2021 *)
%K A115525 easy,sign
%O A115525 0,3
%A A115525 _Paul Barry_, Jan 25 2006