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 A024197 #21 Dec 16 2017 15:29:42 %S A024197 15,176,950,3480,10045,24640,53676,106800,197835,345840,576290,922376, %T A024197 1426425,2141440,3132760,4479840,6278151,8641200,11702670,15618680, %U A024197 20570165,26765376,34442500,43872400,55361475,69254640,85938426,105844200,129451505 %N A024197 a(n) = 3rd elementary symmetric function of the first n+2 odd positive integers. %H A024197 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1). %H A024197 Wolfdieter Lang, <a href="https://arxiv.org/abs/1708.01421">On Generating functions of Diagonals Sequences of Sheffer and Riordan Number Triangles</a>, arXiv:1708.01421 [math.NT], August 2017. %F A024197 a(n) = n*(n+1)*(n+2)^2*(n^2+3*n+1)/6. %F A024197 G.f.: -x*(x^3+33*x^2+71*x+15) / (x-1)^7. - _Colin Barker_, Aug 15 2014 %F A024197 a(n) = A004320(n)*A028387(n). - _R. J. Mathar_, Oct 01 2016 %F A024197 a(n) = A028338(n+2, n-1), n >= 1, (fourth diagonal). See a crossref. below. - _Wolfdieter Lang_, Jul 21 2017 %o A024197 (PARI) Vec(-x*(x^3+33*x^2+71*x+15)/(x-1)^7 + O(x^100)) \\ _Colin Barker_, Aug 15 2014 %Y A024197 Contribution from _Johannes W. Meijer_, Jun 08 2009: (Start) %Y A024197 Equals fourth right hand column of A028338 triangle. %Y A024197 Equals fourth left hand column of A109692 triangle. %Y A024197 Equals fourth right hand column of A161198 triangle divided by 2^m. %Y A024197 (End) %K A024197 nonn,easy %O A024197 1,1 %A A024197 _Clark Kimberling_