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 A357012 #4 Sep 09 2022 04:05:45 %S A357012 1,0,1,0,4,2,0,16,8,5,0,64,32,20,14,0,256,128,80,56,42,0,1024,512,320, %T A357012 224,168,132,0,4096,2048,1280,896,672,528,429,0,16384,8192,5120,3584, %U A357012 2688,2112,1716,1430,0,65536,32768,20480,14336,10752,8448,6864,5720,4862 %N A357012 Triangle read by rows. T(n, k) = [x^k](0^n + 4^n * ((2 - 2*(1 - x)^(1/2)) / x - 1)). %F A357012 T(n, 0) = 0^n, T(n, n) = CatalanNumber(n), otherwise T(n, k) = 4^(n - k)*T(k, k). %e A357012 [0] 1; %e A357012 [1] 0, 1; %e A357012 [2] 0, 4, 2; %e A357012 [3] 0, 16, 8, 5; %e A357012 [4] 0, 64, 32, 20, 14; %e A357012 [5] 0, 256, 128, 80, 56, 42; %e A357012 [6] 0, 1024, 512, 320, 224, 168, 132; %e A357012 [7] 0, 4096, 2048, 1280, 896, 672, 528, 429; %e A357012 [8] 0, 16384, 8192, 5120, 3584, 2688, 2112, 1716, 1430; %e A357012 [9] 0, 65536, 32768, 20480, 14336, 10752, 8448, 6864, 5720, 4862; %p A357012 ogf := n -> 0^n + 4^n * ((2 - 2*(1 - x)^(1/2)) / x - 1): %p A357012 ser := n -> series(ogf(n), x, 32): %p A357012 seq(lprint([n], seq(coeff(ser(n), x, k), k = 0..n)), n = 0..9); %Y A357012 Cf. A000108, A000302, A008549 (row sums), A356651. %K A357012 nonn,tabl %O A357012 0,5 %A A357012 _Peter Luschny_, Sep 09 2022