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 A161954 #9 Mar 17 2025 22:16:36
%S A161954 1,27,377,3627,27026,166230,878409,4098483,17222607,66165501,
%T A161954 235124461,780112671,2435132466,7196829486,20245295242,54455027238,
%U A161954 140596223184,349621224120,839832229131,1953829030737,4412447681628,9693085025844,20750619208890,43361428085886
%N A161954 Number of reduced words of length n in the Weyl group B_27.
%C A161954 Computed with MAGMA using commands similar to those used to compute A161409.
%D A161954 J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
%D A161954 N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche II.)
%H A161954 Andrew Howroyd, <a href="/A161954/b161954.txt">Table of n, a(n) for n = 0..729</a>
%F A161954 G.f. for B_m is the polynomial Prod_{k=1..m}(1-x^(2k))/(1-x). Only finitely many terms are nonzero. This is a row of the triangle in A128084.
%Y A161954 Row n=27 of A128084.
%K A161954 nonn,fini,full
%O A161954 0,2
%A A161954 _John Cannon_ and _N. J. A. Sloane_, Nov 30 2009