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 A279009 #12 Oct 05 2018 03:47:55
%S A279009 1,1,1,-2,0,1,-2,-2,-1,1,4,0,-1,-2,1,4,4,1,1,-3,1,-8,0,3,0,4,-4,1,-8,
%T A279009 -8,-3,3,-4,8,-5,1,16,0,-5,-6,7,-12,13,-6,1,16,16,5,1,-13,19,-25,19,
%U A279009 -7,1,-32,0,11,4,14,-32,44,-44,26,-8,1
%N A279009 Alternating Jacobsthal triangle A_{-2}(n,k) read by rows.
%H A279009 Kyu-Hwan Lee, Se-jin Oh, <a href="http://arxiv.org/abs/1601.06685">Catalan triangle numbers and binomial coefficients</a>, arXiv:1601.06685 [math.CO], 2016.
%e A279009 Triangle begins:
%e A279009 1,
%e A279009 1, 1,
%e A279009 -2, 0, 1,
%e A279009 -2, -2, -1, 1,
%e A279009 4, 0, -1, -2, 1,
%e A279009 4, 4, 1, 1, -3, 1,
%e A279009 -8, 0, 3, 0, 4, - 4, 1,
%e A279009 -8, -8, -3, 3, -4, 8, -5, 1,
%e A279009 16, 0, -5, -6, 7, -12, 13, -6, 1,
%e A279009 16, 16, 5, 1, -13, 19, -25, 19, -7, 1,
%e A279009 -32, 0, 11, 4, 14, -32, 44, -44, 26, -8, 1,
%e A279009 ...
%t A279009 a[n_, 0] := (-2)^Floor[n/2]; a[n_, n_] = 1; a[n_, k_] /; 0 <= k <= n := a[n, k] = a[n-1, k-1] - a[n-1, k]; a[_, _] = 0;
%t A279009 Table[a[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* _Jean-François Alcover_, Oct 05 2018 *)
%Y A279009 Cf. A112468, A279006, A279010.
%K A279009 sign,tabl
%O A279009 0,4
%A A279009 _N. J. A. Sloane_, Dec 07 2016