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 A213760 #16 Feb 13 2024 12:44:28
%S A213760 1,4,12,27,52,92,148,230,335,480,656,889,1162,1512,1912,2412,2973,
%T A213760 3660,4420,5335,6336,7524,8812,10322,11947,13832,15848,18165,20630,
%U A213760 23440,26416,29784,33337,37332,41532,46227,51148,56620,62340,68670
%N A213760 Antidiagonal sums of the convolution array A213783.
%H A213760 Clark Kimberling, <a href="/A213760/b213760.txt">Table of n, a(n) for n = 1..1000</a>
%H A213760 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (2,2,-6,0,6,-2,-2,1).
%F A213760 a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) -2*a(n-7) +a(n-8).
%F A213760 G.f.: f(x)/g(x), where f(x) = x*(1 + 2*x + 2*x^2 + x^3 -2*x^4) and g(x) = (1 + x)^3 *(1 - x)^5.
%F A213760 From _Colin Barker_, May 04 2017: (Start)
%F A213760 a(n) = (2*n^4 + 22*n^3 + 40*n^2 + 8*n) / 96 for n even.
%F A213760 a(n) = (2*n^4 + 22*n^3 + 34*n^2 + 26*n + 12) / 96 for n odd.
%F A213760 (End)
%t A213760 (See A213783.)
%t A213760 LinearRecurrence[{2,2,-6,0,6,-2,-2,1},{1,4,12,27,52,92,148,230},40] (* _Harvey P. Dale_, Feb 13 2024 *)
%o A213760 (PARI) Vec(x*(1 + x - x^2)*(1 + x + 2*x^2) / ((1 - x)^5*(1 + x)^3) + O(x^60)) \\ _Colin Barker_, May 04 2017
%Y A213760 Cf. A213783, A213500.
%K A213760 nonn,easy
%O A213760 1,2
%A A213760 _Clark Kimberling_, Jun 22 2012