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 A213758 #16 Feb 19 2024 04:55:06 %S A213758 1,9,40,130,355,871,1994,4360,9245,19205,39356,79934,161415,324755, %T A213758 651870,1306596,2616609,5237265,10479280,20964090,41934571,83876479, %U A213758 167761330,335532160,671075045,1342162141,2684337764,5368690550 %N A213758 Antidiagonal sums of the convolution array A213756. %H A213758 Clark Kimberling, <a href="/A213758/b213758.txt">Table of n, a(n) for n = 1..100</a> %H A213758 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (6,-14,16,-9,2). %F A213758 a(n) = (1/6)*(-120 + 15*2^(n+3) - 81*n - 21*n^2 - 4*n^3). %F A213758 a(n) = 6*a(n-1) - 14*a(n-2) + 16*a(n-3) - 9*a(n-4) + 2*a(n-5). %F A213758 G.f.: f(x)/g(x), where f(x) = x*(1 + 3*x) and g(x) = (1 - 2*x)*(1 - x)^4. %t A213758 (See A213756.) %Y A213758 Cf. A213756, A213500. %K A213758 nonn,easy %O A213758 1,2 %A A213758 _Clark Kimberling_, Jun 20 2012