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 A140168 #5 Feb 08 2022 20:01:33 %S A140168 1,2,1,4,1,1,8,3,3,1,16,5,9,2,1,32,11,23,7,4,1,64,21,57,16,15,3,1,128, %T A140168 43,135,41,46,12,5,1,256,85,313,94,133,34,22,4,1,512,171,711,219,360, %U A140168 99,78,18,6,1,1024,341,1593,492,939,261,255,60,30,5,1,2048,683,3527,1101 %N A140168 Triangle read by rows, iterates of X * [1,0,0,0,...]; where X = an infinite bidiagonal matrix with [2, -1, 2, -1, 2, ...] in the main diagonal, [1, 1, 1, ...] in the subdiagonal and rest zeros. %C A140168 Row sums = A105476 starting (1, 3, 6, 15, 33, 78, 177, ...). %F A140168 Triangle read by rows, iterates of X * [1,0,0,0,...]; where X = an infinite bidiagonal matrix with [2, -1, 2, -1, 2, ...] in the main diagonal, [1, 1, 1, ...] in the subdiagonal and rest zeros. %e A140168 First few rows of the triangle: %e A140168 1; %e A140168 2, 1; %e A140168 4, 1, 1; %e A140168 8, 3, 3, 1; %e A140168 16, 5, 9, 2, 1; %e A140168 32, 11, 23, 7, 4, 1; %e A140168 64, 21, 57, 16, 15, 3, 1; %e A140168 128, 43, 135, 41, 46, 12, 5, 1; %e A140168 256, 85, 313, 94, 133, 34, 22, 4, 1; %e A140168 512, 171, 711, 219, 360, 99, 78, 18, 6, 1; %e A140168 ... %Y A140168 Cf. A105476. %K A140168 nonn,tabl %O A140168 0,2 %A A140168 _Gary W. Adamson_, May 10 2008