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 A300628 #31 Feb 24 2023 11:25:09
%S A300628 1,2,2,6,5,5,16,16,16,16,52,51,51,51,51,172,170,170,172,170,170,586,
%T A300628 585,585,585,585,585,585,2048,2048,2048,2048,2048,2048,2048,2048,7286,
%U A300628 7280,7280,7285,7280,7280,7285,7280,7280,26216,26214,26214,26214,26214,26216,26214,26214,26214,26214
%N A300628 Triangular array T(n,k) giving coefficients in expansion of Product_{j=1..n} (1+x^j)^2 mod x^(n+1)-1.
%H A300628 Seiichi Manyama, <a href="/A300628/b300628.txt">Rows n = 0..139, flattened</a>
%e A300628 Triangle begins: A053633
%e A300628 k 0 1 2 3 4 | k 0 1 2 3 4 5 6 7 8 9
%e A300628 n |n
%e A300628 0 1; |1 1, 1;
%e A300628 1 2, 2; |3 2, 2, 2, 2;
%e A300628 2 6, 5, 5; |5 6, 5, 5, 6, 5, 5;
%e A300628 3 16, 16, 16, 16; |7 16, 16, 16, 16, 16, 16, 16, 16;
%e A300628 4 52, 51, 51, 51, 51; |9 52, 51, 51, 51, 51, 52, 51, 51, 51, 51;
%e A300628 ... | ...
%o A300628 (PARI) T(n,k) = polcoeff(prod(j=1, n, (1+x^j)^2) % (x^(n+1) - 1), k);
%o A300628 tabl(nn) = for (n=0, nn, for (k=0, n, print1(T(n, k), ", ")); print); \\ _Michel Marcus_, Mar 10 2018
%Y A300628 Cf. A053633, A054660, A298983.
%K A300628 nonn,tabl
%O A300628 0,2
%A A300628 _Seiichi Manyama_, Mar 10 2018