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 A047170 #8 Apr 11 2021 22:16:07
%S A047170 0,0,0,0,0,0,0,0,0,5,6,36,42,147,168,448,504,1134,1260,2565,2827,5687,
%T A047170 6270,13860,15444,39039,44044,119119,135135,360815,408968,1039808,
%U A047170 1174224,2842604,3197904,7515054,8436114,19773414,22203020,53093125,59750649,146794494
%N A047170 Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= n/2.
%H A047170 Andrew Howroyd, <a href="/A047170/b047170.txt">Table of n, a(n) for n = 1..500</a>
%F A047170 a(n) = Sum_{k>=1} binomial(floor(n/2), 5*k)*binomial(ceiling(n/2), k). - _Andrew Howroyd_, Apr 11 2021
%o A047170 (PARI) a(n) = {my(m=n\2); sum(k=1, m\5, binomial(m, 5*k)*binomial(n-m, k))} \\ _Andrew Howroyd_, Apr 11 2021
%Y A047170 Cf. A047169.
%K A047170 nonn
%O A047170 1,10
%A A047170 _Clark Kimberling_
%E A047170 Terms a(35) and beyond from _Andrew Howroyd_, Apr 11 2021