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 A144159 #4 Dec 26 2023 23:55:30 %S A144159 1,1,1,2,1,2,2,2,2,5,3,2,4,5,11,3,3,4,10,11,25,4,3,6,10,22,25,56,4,4, %T A144159 6,15,22,50,56,126,5,4,8,15,33,50,112,126,283,5,5,8,20,33,75,112,252, %U A144159 283,636 %N A144159 Eigentriangle, sum of row n terms = A006054(n+2). %C A144159 Left border = (1, 1, 2, 2, 3, 3,...) Row sums = (1, 2, 5, 11, 25, 56, 126,...) = A006054 such that row n = A006054(n+2). %C A144159 Sum of n-th row terms = rightmost term of next row. %F A144159 Triangle read by rows, A * B, where A = an infinite lower triangular matrix with A008619: (1, 1, 2, 2, 3, 3,...) in every column. B = an infinite lower triangular matrix with A008619 as the main diagonal: (1, 2, 5, 11, 25, 56, 126,...) and the rest zeros. %e A144159 First few rows of the triangle = %e A144159 1; %e A144159 1, 1; %e A144159 2, 1, 2; %e A144159 2, 2, 2, 5; %e A144159 3, 2, 4, 5, 11; %e A144159 3, 3, 4, 10, 11, 25; %e A144159 4, 3, 6, 10, 22, 25, 56; %e A144159 4, 4, 6, 15, 22, 50, 56, 126; %e A144159 5, 4, 8, 15, 33, 50, 112, 126, 283; %e A144159 ... %Y A144159 Cf. A006054, A008619. %K A144159 nonn,tabl %O A144159 1,4 %A A144159 _Gary W. Adamson_, Sep 12 2008