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%I #15 Jun 01 2020 04:37:19
%S 1,64,2704,102400,3748096,135675904,4893282304,176265625600,
%T 6346852335616,228502162898944,8226263614357504,296147719133593600,
%U 10661344637077159936,383808727914259677184,13817118056668205154304,497416296261117961830400,17906987220053014721069056
%N a(n) = (6^n - 2^n)^2 / 16.
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (52,-624,1728).
%F From _R. J. Mathar_, Sep 24 2008: (Start)
%F a(n) = 81*36^(n-2) + 4^(n-2) - 18*12^(n-2).
%F G.f.: x*(1+12x)/((1-36x)*(1-4x)*(1-12x)). (End)
%F a(n) = A016129(n-1)^2. - _Philippe Deléham_, Nov 26 2008
%t Table[(6^n-2^n)^2/16,{n,20}] (* or *) Table[4^(n-2) (3^n-1)^2,{n,20}] (* _Harvey P. Dale_, Apr 15 2020 *)
%K nonn,easy
%O 1,2
%A Al Hakanson (hawkuu(AT)gmail.com), Sep 22 2008
%E More terms from _R. J. Mathar_, Sep 24 2008
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