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 A188168 #10 Nov 19 2024 16:53:19
%S A188168 1,1,10,55,325,1900,11125,65125,381250,2231875,13065625,76487500,
%T A188168 447765625,2621265625,15345156250,89832109375,525886328125,
%U A188168 3078592187500,18022392578125,105504923828125,617636582031250,3615707529296875,21166720556640625
%N A188168 a(0) = a(1) = 1; a(n) = 5*a(n-1) + 5*a(n-2).
%C A188168 First differences give {0,9,45,270,1575,9225,54000,316125,1850625,10833750,63421875,371278125, . . .}
%H A188168 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,5).
%F A188168 G.f.: (4x-1)/(5x^2+5x-1)
%F A188168 a(n) = 1/5 2^-n (-(5-3 Sqrt[5])^n (2+Sqrt[5])+(-2+Sqrt[5]) (5+3 Sqrt[5])^n)
%t A188168 Transpose[NestList[Flatten[{Rest[#],ListCorrelate[{5,5},#]}]&, {1,1},40]][[1]]
%t A188168 LinearRecurrence[{5,5},{1,1},30] (* _Harvey P. Dale_, Nov 19 2024 *)
%Y A188168 Cf. A123270.
%K A188168 nonn,easy
%O A188168 0,3
%A A188168 _Harvey P. Dale_, Mar 23 2011