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 A382974 #12 Apr 11 2025 07:55:39
%S A382974 1,-1,1,0,-2,2,-1,2,-4,3,1,-3,4,-7,5,-1,4,-8,10,-12,7,1,-5,14,-20,18,
%T A382974 -19,11,-1,6,-18,34,-40,34,-30,15,2,-7,22,-51,78,-77,56,-45,22,-2,9,
%U A382974 -30,75,-127,157,-139,94,-67,30,2,-11,42,-105,196,-282,306,-239,146,-97,42
%N A382974 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where A(n,k) = [x^n * y^k] Product_{j>=1} 1/(1 - x^j + y^j).
%e A382974 Square array begins:
%e A382974 1, -1, 0, -1, 1, -1, 1, ...
%e A382974 1, -2, 2, -3, 4, -5, 6, ...
%e A382974 2, -4, 4, -8, 14, -18, 22, ...
%e A382974 3, -7, 10, -20, 34, -51, 75, ...
%e A382974 5, -12, 18, -40, 78, -127, 196, ...
%e A382974 7, -19, 34, -77, 157, -282, 478, ...
%e A382974 11, -30, 56, -139, 306, -582, 1048, ...
%Y A382974 Columns k=0..1 give A000041, (-1)*A000070.
%Y A382974 Rows n=0..1 give A081362, (-1)^k * A304631(k).
%Y A382974 Main diagonal gives A382979.
%Y A382974 Antidiagonal sums give A000007.
%Y A382974 Cf. A322210.
%K A382974 sign,tabl
%O A382974 0,5
%A A382974 _Seiichi Manyama_, Apr 11 2025