%I #11 Mar 17 2023 14:55:50
%S 1,1,1,-3,-9,-9,-6,10,25,25,15,-21,-49,-49,-28,36,81,81,45,-55,-121,
%T -121,-66,78,169,169,91,-105,-225,-225,-120,136,289,289,153,-171,-361,
%U -361,-190,210,441,441,231,-253,-529,-529,-276,300,625,625,325
%N Expansion of (1+x)*(1+x+x^2)*(1-x+x^2-4*x+x^4-x^5+x^6)/(1+x^4)^3.
%C a(n+1) is the Hankel transform of A166300(n+3) (diagonal sums of the triangle A100754).
%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,-3,0,0,0,-3,0,0,0,-1).
%F G.f.: (1+x+x^2-3*x^3-6*x^4-6*x^5-3*x^6+x^7+x^8+x^9)/(1+x^4)^3.
%F a(n) = -3*a(n-4) - 3*a(n-8) - a(n-12). - _Wesley Ivan Hurt_, Mar 17 2023
%K sign,easy
%O 0,4
%A _Paul Barry_, Mar 31 2011