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 A024223 #7 Jun 25 2019 22:22:01
%S A024223 1,12,45,115,244,457,785,1262,1926,2822,3997,5504,7400,9746,12608,
%T A024223 16057,20168,25021,30699,37290,44888,53591,63500,74722,87368,101553,
%U A024223 117397,135026,154567,176154,199926,226024,254597,285795,319774,356694,396722,440026
%N A024223 [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 1 mod 3}.
%F A024223 a(n) = floor(A024214(n) / A024212(n+2)). - _Sean A. Irvine_, Jun 25 2019
%K A024223 nonn
%O A024223 1,2
%A A024223 _Clark Kimberling_