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 A295343 #4 Nov 20 2017 22:00:24
%S A295343 1,1,0,1,-1,0,1,-1,1,0,1,-1,0,-1,0,1,-1,0,2,1,0,1,-1,0,1,-2,-1,0,1,-1,
%T A295343 0,1,2,-6,1,0,1,-1,0,1,1,-6,16,-1,0,1,-1,0,1,1,-1,-14,20,1,0,1,-1,0,1,
%U A295343 1,-2,-14,20,-132,-1,0,1,-1,0,1,1,-2,-8,-15,204,-28,1,0,1,-1,0,1,1,-2,-9,-15,99,28,1216,-1,0
%N A295343 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(-Sum_{j=1..k} x^j/j!).
%F A295343 E.g.f. of column k: exp(-Sum_{j=1..k} x^j/j!).
%e A295343 Square array begins:
%e A295343 1, 1, 1, 1, 1, 1, ...
%e A295343 0, -1 -1, -1, -1, -1, ...
%e A295343 0, 1, 0, 0, 0, 0, ...
%e A295343 0, -1, 2, 1, 1, 1, ...
%e A295343 0, 1, -2, 2, 1, 1, ...
%e A295343 0, -1, -6, -6, -1, -2, ...
%t A295343 Table[Function[k, n! SeriesCoefficient[Exp[-Sum[x^i/i!, {i, 1, k}]], {x, 0, n}]][j - n], {j, 0, 12}, {n, 0, j}] // Flatten
%t A295343 Table[Function[k, n! SeriesCoefficient[Exp[1 - Exp[x] Gamma[k + 1, x]/Gamma[k + 1]], {x, 0, n}]][j - n], {j, 0, 12}, {n, 0, j}] // Flatten
%Y A295343 Columns k=0..3 give A000007, A033999, A001464, A014775.
%Y A295343 Main diagonal gives A000587.
%Y A295343 Cf. A229223.
%K A295343 sign,tabl
%O A295343 0,19
%A A295343 _Ilya Gutkovskiy_, Nov 20 2017