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 A127251 #8 Aug 04 2023 04:35:35
%S A127251 1,-2,1,2,-2,1,0,0,0,1,0,0,0,-2,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,
%T A127251 0,-2,1,0,0,0,0,0,0,2,-2,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,
%U A127251 0,0,0,0,0,0,0,0,0,0,-2,1,0,0,0,0,0,0,0,0,0,0,0,0,1
%N A127251 Inverse of number triangle A127249.
%e A127251 Triangle begins:
%e A127251 1;
%e A127251 -2, 1;
%e A127251 2, -2, 1;
%e A127251 0, 0, 0, 1;
%e A127251 0, 0, 0, -2, 1;
%e A127251 0, 0, 0, 0, 0, 1;
%e A127251 0, 0, 0, 0, 0, 0, 1;
%e A127251 0, 0, 0, 0, 0, 0, -2, 1;
%e A127251 0, 0, 0, 0, 0, 0, 2, -2, 1;
%e A127251 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e A127251 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e A127251 ...
%t A127251 T1[n_, k_] := SeriesCoefficient[(1 - ThueMorse[1 + k]*x)*x^k, {x, 0, n}]; (* A127248 *)
%t A127251 T2[n_, k_] := (-1)^(n-k) * Product[ThueMorse[i], {i, k+1, n}]; (* A127244 *)
%t A127251 T[n_, k_] := Sum[T2[n, j]*T1[j, k], {j, 0, n}];
%t A127251 Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* _Amiram Eldar_, Aug 04 2023 *)
%Y A127251 Product of A127248 and A127244.
%Y A127251 Row sums are A127252.
%Y A127251 Cf. A127249.
%K A127251 sign,tabl
%O A127251 0,2
%A A127251 _Paul Barry_, Jan 10 2007
%E A127251 More terms from _Amiram Eldar_, Aug 04 2023