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 A024390 #14 Jul 06 2019 20:59:55
%S A024390 0,2,5,10,15,21,28,37,46,56,67,80,93,107,122,138,156,174,193,213,235,
%T A024390 257,280,304,330,356,383,411,441,471,502,534,568,602,637,673,711,749,
%U A024390 788,828,870,912,955,999,1045,1091,1138,1186,1236,1286,1337
%N A024390 [ (4th elementary symmetric function of S(n))/(3rd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 1 mod 4}.
%F A024390 Empirical g.f.: x^2*(x^16-2*x^15+x^14+x^4-2*x^2-x-2) / ((x-1)^3*(x+1)*(x^2+1)). - _Colin Barker_, Aug 16 2014
%F A024390 a(n) = floor(A024380(n) / A024379(n+1)). - _Sean A. Irvine_, Jul 06 2019
%Y A024390 Cf. A024379, A024380.
%K A024390 nonn
%O A024390 1,2
%A A024390 _Clark Kimberling_
%E A024390 More terms from _Sean A. Irvine_, Jul 06 2019