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 A337355 #24 Sep 03 2020 12:18:17
%S A337355 1,1,2,3,6,5,5,63,56,4,225,77,1232,312,65,2695,1408,14144,9945,92169,
%T A337355 53504,28288,41769,370139,447488,217600,502775,1427679,2684928,
%U A337355 2524160,10414625,132774147,443908096,2375680,1168520925,3129357,18644140032,35160064,1108596775,2318853537
%N A337355 a(n) is the denominator of Product_{i=0..n-1} (n-i)^((-1)^ceiling(i/2)).
%e A337355 a(5) = denominator of (5*2)/(4*3) = 6.
%o A337355 (PARI) a(n) = {denominator(prod(i=0, n-1, (n-i)^(-1)^((i+1)\2)))} \\ _Andrew Howroyd_, Aug 25 2020
%Y A337355 Cf. A337354 (numerators).
%K A337355 nonn,frac
%O A337355 1,3
%A A337355 _Devansh Singh_, Aug 24 2020
%E A337355 Terms a(31) and beyond from _Andrew Howroyd_, Aug 25 2020