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 A213818 #16 Jan 04 2022 20:58:52 %S A213818 1,12,60,190,465,966,1792,3060,4905,7480,10956,15522,21385,28770, %T A213818 37920,49096,62577,78660,97660,119910,145761,175582,209760,248700, %U A213818 292825,342576,398412,460810,530265,607290,692416 %N A213818 Antidiagonal sums of the convolution array A213773. %H A213818 Clark Kimberling, <a href="/A213818/b213818.txt">Table of n, a(n) for n = 1..299</a> %H A213818 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1). %F A213818 a(n) = (2*n - n^2 + 3*n^4)/4. %F A213818 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). %F A213818 G.f.: f(x)/g(x), where f(x) = x*(1 + 7*x + 10*x^2) and g(x) = (1-x)^5. %F A213818 a(n) = A000217(n) * A005448(n). - _John Elias_, Jan 04 2022 %t A213818 (See A213773.) %Y A213818 Cf. A213773. %K A213818 nonn,easy %O A213818 1,2 %A A213818 _Clark Kimberling_, Jul 04 2012