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 A017867 #34 May 29 2025 16:43:00
%S A017867 1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,2,1,0,0,0,0,0,1,3,3,1,0,0,0,0,1,4,
%T A017867 6,4,1,0,0,0,1,5,10,10,5,1,0,0,1,6,15,20,15,6,1,0,1,7,21,35,35,21,7,1,
%U A017867 1,8,28,56,70,56,28,8,2,9
%N A017867 Expansion of 1/(1 - x^8 - x^9).
%C A017867 Number of compositions of n into parts 8 and 9. - _Joerg Arndt_, Jun 29 2013
%H A017867 Vincenzo Librandi, <a href="/A017867/b017867.txt">Table of n, a(n) for n = 0..1000</a>
%H A017867 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,1,1).
%F A017867 a(n) = a(n-8) + a(n-9) for n>8. - _Vincenzo Librandi_, Jun 28 2013
%F A017867 a(n) = Sum_{k=0..floor(n/8)} binomial(k,n-8*k). - _Seiichi Manyama_, Oct 01 2024
%t A017867 CoefficientList[Series[1 / (1 - Total[x^Range[8, 9]]), {x, 0, 80}], x] (* _Vincenzo Librandi_, Jun 28 2013 *)
%o A017867 (Magma) m:=80; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^8-x^9))); // _Vincenzo Librandi_, Jun 28 2013
%o A017867 (Magma) I:=[1,0,0,0,0,0,0,0,1]; [n le 9 select I[n] else Self(n-8)+Self(n-9): n in [1..80]]; // _Vincenzo Librandi_, Jun 28 2013
%o A017867 (PARI) x='x+O('x^66); Vec(1/(1-x^8-x^9)) \\ _Altug Alkan_, Oct 07 2018
%Y A017867 Column k=8 of A306713.
%Y A017867 Cf. A017817, A017827, A017857, A017877.
%K A017867 nonn,easy
%O A017867 0,18
%A A017867 _N. J. A. Sloane_