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 A013984 #27 Jul 08 2025 02:51:49
%S A013984 1,0,1,1,2,3,5,8,12,20,31,50,79,126,200,318,506,804,1279,2033,3233,
%T A013984 5140,8173,12995,20662,32853,52236,83056,132059,209975,333861,530841,
%U A013984 844040,1342028,2133832,3392804,5394577
%N A013984 Expansion of 1/(1-x^2-x^3-x^4-x^5-x^6-x^7).
%C A013984 Number of compositions of n into parts p where 2 <= p < = 7. [_Joerg Arndt_, Jun 24 2013]
%H A013984 Vincenzo Librandi, <a href="/A013984/b013984.txt">Table of n, a(n) for n = 0..1000</a>
%H A013984 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,1,1,1,1,1,1)
%t A013984 CoefficientList[Series[1 / (1 - x^2 - x^3 - x^4 - x^5 - x^6 - x^7), {x, 0, 40}], x] (* _Vincenzo Librandi_, Jun 23 2013 *)
%o A013984 (PARI) Vec(1/(1-x^2-x^3-x^4-x^5-x^6-x^7)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 25 2012
%o A013984 (Magma) m:=40; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^2-x^3-x^4-x^5-x^6-x^7))); // _Vincenzo Librandi_, Jun 24 2013
%K A013984 nonn,easy
%O A013984 0,5
%A A013984 _N. J. A. Sloane_