%I #19 Aug 30 2022 06:40:56
%S 0,0,1,1,15,17,239,273,3823,4369,61167,69905,978671,1118481,15658735,
%T 17895697,250539759,286331153,4008636143,4581298449,64138178287,
%U 73300775185,1026210852591,1172812402961,16419373641455,18764998447377
%N a(0) = 0 and a(n) = (5*(-4)^n + 16*(-1)^n + 9*4^n)/240 for n >= 1.
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (-1,16,16).
%F From _Colin Barker_, Dec 03 2012: (Start)
%F a(n) = (5*(-4)^n + 16*(-1)^n + 9*4^n)/240 for n>0.
%F G.f.: -x^2*(2*x+1) / ((x+1)*(4*x-1)*(4*x+1)). (End)
%t a[n_] := If[n == 0, 1, (5(-4)^n + 16(-1)^n + 9*4^n) / 240];
%t a /@ Range[0, 25] (* _Jean-François Alcover_, Mar 30 2021 *)
%Y Cf. A112627.
%K nonn,easy
%O 0,5
%A _Roger L. Bagula_, Jan 31 2006
%E New name (using _Colin Barker_'s formula) from _Joerg Arndt_, Aug 30 2022