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 A097556 #12 Apr 21 2021 02:27:36
%S A097556 1,9,56,279,1223,4932,18833,69345,249166,880525,3076295,10662459,
%T A097556 36749785,126161246,431880044,1475412473,5032964258,17150277106,
%U A097556 58395929325,198723871661,675989712225,2298799014859,7815699898677,26568450635871
%N A097556 Number of positive words of length n in the monoid Br_9 of positive braids on 10 strands.
%H A097556 G. C. Greubel, <a href="/A097556/b097556.txt">Table of n, a(n) for n = 0..1000</a>
%H A097556 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9,-32,63,-84,81,-56,27,-8,1).
%F A097556 G.f.: (1 +x^2)^7/(1 -9*x +32*x^2 -63*x^3 +84*x^4 -81*x^5 +56*x^6 -27*x^7 +8*x^8 -x^9).
%t A097556 CoefficientList[Series[(1+x^2)^7/(1-9*x+32*x^2-63*x^3+84*x^4-81*x^5+56*x^6-27*x^7+8*x^8-x^9), {x,0,50}], x] (* _G. C. Greubel_, Apr 20 2021 *)
%o A097556 (Magma)
%o A097556 R<x>:=PowerSeriesRing(Integers(), 50);
%o A097556 Coefficients(R!( (1+x^2)^7/(1-9*x+32*x^2-63*x^3+84*x^4-81*x^5+56*x^6-27*x^7+8*x^8-x^9) )); // _G. C. Greubel_, Apr 20 2021
%o A097556 (Sage)
%o A097556 def A097556_list(prec):
%o A097556 P.<x> = PowerSeriesRing(ZZ, prec)
%o A097556 return P( (1+x^2)^7/(1-9*x+32*x^2-63*x^3+84*x^4-81*x^5+56*x^6-27*x^7+8*x^8-x^9) ).list()
%o A097556 A097556_list(50) # _G. C. Greubel_, Apr 20 2021
%Y A097556 Cf. A097550, A097551, A097552, A097553, A097554, A097555.
%K A097556 nonn,easy
%O A097556 0,2
%A A097556 _D n Verma_, Aug 16 2004
%E A097556 Edited and extended by _Max Alekseyev_, Jun 17 2011