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 A251705 #23 Mar 28 2025 10:25:08
%S A251705 1,1,1,0,3,5,9,17,34,65,125,241,465,896,1727,3329,6417,12369,23842,
%T A251705 45957,88585,170753,329137,634432,1222907,2357229,4543705,8758273,
%U A251705 16882114,32541321,62725413,120907121,233055969,449229824,865918327,1669111241
%N A251705 4-step Fibonacci sequence starting with 1, 1, 1, 0.
%H A251705 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,1,1).
%F A251705 a(n+4) = a(n) + a(n+1) + a(n+2) + a(n+3).
%F A251705 G.f.: (-1+3*x^3+x^2)/(-1+x+x^2+x^3+x^4) . - _R. J. Mathar_, Mar 28 2025
%t A251705 LinearRecurrence[Table[1, {4}], {1, 1, 1, 0}, 36] (* _Michael De Vlieger_, Dec 09 2014 *)
%o A251705 (J) NB. see A251655 for the program and apply it to 1,1,1,0.
%Y A251705 Other 4-step Fibonacci sequences are A000078, A000288, A001630, A001631, A001648, A073817, A100532, A251654, A251655, A251656, A251703, A251704.
%K A251705 nonn,easy
%O A251705 0,5
%A A251705 _Arie Bos_, Dec 07 2014