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 A170984 #17 Jan 04 2021 04:08:12
%S A170984 1,0,0,1,0,0,0,1,0,0,1,1,0,0,1,1,0,0,2,1,0,1,2,2,0,1,4,1,0,2,4,1,0,4,
%T A170984 5,1,1,5,5,1,1,7,6,1,3,9,6,0,4,11,6,0,7,13,5,1,9,15,5,2,13,16,4,3,16,
%U A170984 17,4,5,21,18,2,8,24,17,2,12,29,16,3,16,31,15,3,21,35,13,4,27,35,11,6,33,37
%N A170984 Expansion of (Product_{i=1..m-1} (1 + x^(4*i-1))) * (1 + x^(2*m-1)) for m = 12.
%C A170984 (Product_{i=1..m-1} (1 + x^(4*i-1))) * (1 + x^(2*m-1)) is the Poincaré polynomial for O(2m).
%D A170984 H. Weyl, The Classical Groups, Princeton, 1946, see p. 238.
%H A170984 Nathaniel Johnston, <a href="/A170984/b170984.txt">Table of n, a(n) for n = 0..276</a>
%o A170984 (PARI) my(m=12, x='x+O('x^275)); Vec((1+x^(2*m-1))*prod(i=1, m-1, 1+x^(4*i-1))) \\ _Jinyuan Wang_, Mar 08 2020
%K A170984 nonn,fini,full,easy
%O A170984 0,19
%A A170984 _N. J. A. Sloane_, Aug 29 2010