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 A293019 #12 Sep 30 2017 04:39:45
%S A293019 1,1,-1,1,-1,0,1,0,-1,1,1,0,-2,2,1,1,0,0,-6,9,-2,1,0,0,-6,0,4,-9,1,0,
%T A293019 0,0,-24,100,-95,-9,1,0,0,0,-24,-60,570,-414,50,1,0,0,0,0,-120,240,
%U A293019 798,49,267,1,0,0,0,0,-120,-360,4830,-15176,10088,413,1,0,0
%N A293019 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where A(0,k) = 1 and A(n,k) = - k! * Sum_{i=0..n-1} binomial(n-1,i) * binomial(i+1,k) * A(n-1-i,k) for n > 0.
%H A293019 Seiichi Manyama, <a href="/A293019/b293019.txt">Antidiagonals n = 0..139, flattened</a>
%e A293019 Square array begins:
%e A293019 1, 1, 1, 1, 1, ...
%e A293019 -1, -1, 0, 0, 0, ...
%e A293019 0, -1, -2, 0, 0, ...
%e A293019 1, 2, -6, -6, 0, ...
%e A293019 1, 9, 0, -24, -24, ...
%Y A293019 Columns k=0-4 give: A000587, A292952, A293016, A293017, A293018.
%Y A293019 Rows n=0 gives A000012.
%Y A293019 Cf. A292978, A293015.
%K A293019 sign,tabl
%O A293019 0,13
%A A293019 _Seiichi Manyama_, Sep 28 2017