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 A178114 #10 Jan 30 2020 21:29:16
%S A178114 1,1,-1,-3,0,8,6,-21,-37,45,175,-22,-703,-533,2370,4321,-5930,-23560,
%T A178114 3534,104035,81083,-376267,-705158,993738,4047745,-604007,-18622243,
%U A178114 -14895477,69622834,133284470,-188549209,-784970693,110402283
%N A178114 Expansion of (sqrt(1-2x+7x^2-6x^3+5x^4)-(1-x+x^2))/(2x^2(1-x+x^2)).
%C A178114 Hankel transform is A178115.
%F A178114 D-finite with recurrence: +(n+2)*a(n) +2*(-n-1)*a(n-1) +(7*n-4)*a(n-2) +2*(-3*n+4)*a(n-3) +5*(n-2)*a(n-4)=0. - _R. J. Mathar_, Feb 10 2015
%t A178114 CoefficientList[Series[(Sqrt[1-2x+7x^2-6x^3+5x^4]-(1-x+x^2))/(2x^2 (1-x+x^2)),{x,0,40}],x] (* _Harvey P. Dale_, Dec 01 2013 *)
%K A178114 easy,sign
%O A178114 0,4
%A A178114 _Paul Barry_, May 20 2010