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 A292130 #14 Sep 09 2017 12:15:35 %S A292130 1,0,-3,0,-3,0,-3,9,0,-3,9,0,-3,18,0,-3,18,-27,0,-3,27,-27,0,-3,27, %T A292130 -54,0,-3,36,-81,0,-3,36,-108,81,0,-3,45,-135,81,0,-3,45,-189,162,0, %U A292130 -3,54,-216,243,0,-3,54,-270,405,0,-3,63,-324,486,-243,0,-3,63,-378 %N A292130 Triangle read by rows: T(n,k) = (-3) * T(n-k,k-1) + T(n-k,k) with T(0,0) = 1 for 0 <= k <= A003056(n). %H A292130 Seiichi Manyama, <a href="/A292130/b292130.txt">Rows n = 0..481, flattened</a> %e A292130 First few rows are: %e A292130 1; %e A292130 0, -3; %e A292130 0, -3; %e A292130 0, -3, 9; %e A292130 0, -3, 9; %e A292130 0, -3, 18; %e A292130 0, -3, 18, -27; %e A292130 0, -3, 27, -27; %e A292130 0, -3, 27, -54; %e A292130 0, -3, 36, -81; %e A292130 0, -3, 36, -108, 81. %Y A292130 Row sums give A292128. %Y A292130 Columns 0-1 give A000007, (-1)*A010701. %Y A292130 Cf. A291971. %K A292130 sign,tabf %O A292130 0,3 %A A292130 _Seiichi Manyama_, Sep 09 2017