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 A251654 #32 Jul 20 2025 20:42:03
%S A251654 0,1,1,0,2,4,7,13,26,50,96,185,357,688,1326,2556,4927,9497,18306,
%T A251654 35286,68016,131105,252713,487120,938954,1809892,3488679,6724645,
%U A251654 12962170,24985386,48160880,92833081,178941517,344920864,664856342,1281551804
%N A251654 4-step Fibonacci sequence starting with 0, 1, 1, 0.
%H A251654 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,1,1).
%F A251654 a(n+4) = a(n) + a(n+1) + a(n+2) + a(n+3).
%F A251654 G.f.: x*(-1+2*x^2)/(-1+x+x^2+x^3+x^4). - _R. J. Mathar_, Mar 28 2025
%F A251654 a(n) = A000078(n+2)-2*A000078(n). - _R. J. Mathar_, Mar 28 2025
%t A251654 LinearRecurrence[Table[1, {4}], {0, 1, 1, 0}, 36] (* _Michael De Vlieger_, Dec 09 2014 *)
%o A251654 (J) NB. see A251655 for the program and apply it to 0,1,1,0.
%Y A251654 Other 4-step Fibonacci sequences are A000078, A000288, A001630, A001631, A001648, A073817, A100532, A251655, A251656, A251672, A251703, A251704, A251705.
%K A251654 nonn,easy
%O A251654 0,5
%A A251654 _Arie Bos_, Dec 06 2014