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 A336203 #13 May 01 2021 17:41:02
%S A336203 1,1,3,1,3,7,1,3,9,15,1,3,13,27,31,1,3,21,63,81,63,1,3,37,171,321,243,
%T A336203 127,1,3,69,495,1521,1683,729,255,1,3,133,1467,7761,14283,8989,2187,
%U A336203 511,1,3,261,4383,41361,131283,138909,48639,6561,1023,1,3,517,13131,227601,1256283,2336629,1385163,265729,19683,2047
%N A336203 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Sum_{j=0..n} 2^j * binomial(n,j)^k.
%C A336203 Column k is the diagonal of the rational function 1 / (Product_{j=1..k} (1-x_j) - 2 * Product_{j=1..k} x_j) for k>0.
%e A336203 Square array begins:
%e A336203 1, 1, 1, 1, 1, 1, ...
%e A336203 3, 3, 3, 3, 3, 3, ...
%e A336203 7, 9, 13, 21, 37, 69, ...
%e A336203 15, 27, 63, 171, 495, 1467, ...
%e A336203 31, 81, 321, 1521, 7761, 41361, ...
%e A336203 63, 243, 1683, 14283, 131283, 1256283, ...
%t A336203 T[n_, k_] := Sum[2^j * Binomial[n, j]^k, {j, 0, n}]; Table[T[k, n-k], {n, 0, 10}, {k, 0, n}] // Flatten (* _Amiram Eldar_, May 01 2021 *)
%Y A336203 Columns k=0-4 give: A000225(n+1), A000244, A001850, A206178, A216696.
%Y A336203 Main diagonal gives A336204.
%Y A336203 Cf. A309010.
%K A336203 nonn,tabl
%O A336203 0,3
%A A336203 _Seiichi Manyama_, Jul 11 2020