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 A353128 #16 Apr 08 2023 14:43:04
%S A353128 0,0,1,4,10,20,35,20,39,48,57,40,61,58,68,92,59,96,105,114,79,118,106,
%T A353128 116,149,98,153,162,171,118,175,154,164,206,137,210,219,228,157,232,
%U A353128 202,212,263,176,267,276,285,196,289,250,260,320,215,324,333,342,235,346
%N A353128 Antidiagonal sums of A353109.
%H A353128 <a href="/index/Rec#order_18">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,-1).
%F A353128 G.f.: x^2*(1 + 4*x + 10*x^2 + 20*x^3 + 35*x^4 + 20*x^5 + 39*x^6 + 48*x^7 + 55*x^9 + 32*x^10 + 41*x^11 + 18*x^12 - 2*x^13 - 19*x^15 + 105*x^17 + x^18 + 3*x^19 + 6*x^20 + 10*x^21 + 15*x^22 + 89*x^23 + 19*x^24 + 9*x^25 - 48*x^26)/((1 - x)^2*(1 + x + x^2)^2*(1 + x^3 + x^6)^2).
%F A353128 a(n) = 2*a(n-9) - a(n-18) for n > 18.
%t A353128 LinearRecurrence[{0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,-1},{0,0,1,4,10,20,35,20,39,48,57,40,61,58,68,92,59,96,105},58]
%Y A353128 Cf. A004247, A010888, A353109, A353933.
%K A353128 nonn,base,easy
%O A353128 0,4
%A A353128 _Stefano Spezia_, Apr 24 2022