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 A144019 #12 Mar 08 2021 16:41:06 %S A144019 1,2,1,5,2,3,12,5,6,10,29,12,15,20,33,70,29,36,50,66,109,169,70,87, %T A144019 120,165,218,360,408,169,210,290,396,545,720,1189,985,408,507,700,957, %U A144019 1308,1800,2378,3927 %N A144019 Eigentriangle read by rows, T(n,k) = A000129(n-k+1)*A006190(k). %C A144019 Row sums = A006190: (1, 3, 10, 33, 109,...) %C A144019 Left border = Pell series, A000129. %C A144019 Right border = A006190 shifted. %F A144019 Triangle read by rows, T(n,k) = A000129(n-k+1)*A006190(k), with A006190 one place to the right, = (1, 1, 3, 10, 33, 109,...). %e A144019 First few rows of the triangle: %e A144019 1; %e A144019 2, 1; %e A144019 5, 2, 3; %e A144019 12, 5, 6, 10; %e A144019 29, 12, 15, 20, 33; %e A144019 70, 29, 36, 50, 66, 109; %e A144019 169, 70, 87, 120, 165, 218, 360; %e A144019 ... %e A144019 Row 4 = (12, 5, 6, 10) = termwise product of (12, 5, 2, 1) and (1, 1, 3, 10) = (12*1, 5*1, 2*3, 1*10). %Y A144019 Cf. A000129, A006190. %K A144019 nonn,tabl %O A144019 1,2 %A A144019 _Gary W. Adamson_, Sep 07 2008