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 A127740 #13 Jan 03 2025 09:32:48 %S A127740 1,2,4,6,9,15,20,28,40,60,75,100,135,185,260,312,402,522,684,906,1218, %T A127740 1421,1785,2254,2863,3661,4718,6139,7016,8640,10680,13256,16528,20712, %U A127740 26104,33120,37260,45153,54873,66888,81801,100395,123696,153063,190323 %N A127740 Natural number transform of Aitken's triangle. %C A127740 Left column (1, 2, 6, 20, ...) = A052889. %C A127740 Row sums give A127741. %F A127740 A127648 * A011971 as infinite lower triangular matrices. %e A127740 First few rows of the triangle: %e A127740 1; %e A127740 2, 4; %e A127740 6, 9, 15; %e A127740 20, 28, 40, 60; %e A127740 75, 100, 135, 185, 260; %e A127740 ... %Y A127740 Cf. A005493, A052889, A011971, A127741. %K A127740 nonn,tabl %O A127740 0,2 %A A127740 _Gary W. Adamson_, Jan 27 2007