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 A160708 #6 Jan 02 2019 10:47:23 %S A160708 1,1,1,3,1,3,18,3,3,18,192,18,9,18,192,3472,192,54,54,192,3472,104964, %T A160708 3472,576,324,576,3472,104964,5606272,104964,10416,3456,3456,10416, %U A160708 104964,5306272 %N A160708 Convolution triangle by rows, row sums = the Robbins sequence, A005130 starting with offset 1. %C A160708 The terms are not integral in general, see A160707. - _Joerg Arndt_, Jan 02 2019 %C A160708 Row sums = the Robbins sequence A005130, starting with offset 1: (1, 2, 7, 42, 429,...). %C A160708 Right and left borders = A160707, the convolution square root of A005130. %F A160708 Let M = an infinite lower triangular Toeplitz matrix with A160707 in every column: (1, 1, 3, 18, 192, 5472,...); where A160707 = the convolution square root of the Robbins sequence: (1, 2, 7, 42, 429, 7436,...). Let Q = an infinite lower triangular matrix with (1, 1, 3, 18, 192,...) as the main diagonal and the rest zeros. Triangle A160708 = M * Q. %e A160708 First few rows of the triangle = %e A160708 1; %e A160708 1, 1; %e A160708 3, 1, 3; %e A160708 18, 3, 3, 18; %e A160708 192, 18, 9, 18, 192; %e A160708 3472, 192, 54, 54, 192, 3472; %e A160708 104964, 3472, 576, 324, 576, 3472, 104964; %e A160708 5606272, 104964, 10416, 3456, 3456, 10416, 104964, 5306272; %e A160708 ... %e A160708 Example: row 5 = (192, 18, 9, 18, 192) = (192, 18, 3, 1, 1) * (1, 1, 3, 18, 192); where A005130(5) = 429 = (192 + 18 + 9 + 18 + 192). %Y A160708 Cf. A005130, A160707 %K A160708 nonn,tabl,less %O A160708 1,4 %A A160708 _Gary W. Adamson_, May 24 2009