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 A096921 #16 Oct 29 2022 04:52:18
%S A096921 1,1,1,1,1,2,1,1,2,3,1,1,3,3,6,1,1,3,4,6,10,1,1,4,4,10,10,20,1,1,4,5,
%T A096921 10,15,20,35,1,1,5,5,15,15,35,35,70,1,1,5,6,15,21,35,56,70,126,1,1,6,
%U A096921 6,21,21,56,56,126,126,252,1,1,6,7,21,28,56,84,126,210,252,462
%N A096921 Triangle array of binomial coefficients.
%F A096921 T(n, k) = binomial(floor((n+k)/2), floor(k/2)).
%e A096921 Triangle begins:
%e A096921 k=0 1 2 3 4 5
%e A096921 n=0: 1;
%e A096921 n=1: 1, 1;
%e A096921 n=2: 1, 1, 2;
%e A096921 n=3: 1, 1, 2, 3;
%e A096921 n=4: 1, 1, 3, 3, 6;
%e A096921 n=5: 1, 1, 3, 4, 6, 10;
%e A096921 ...
%t A096921 T[n_, k_]=Binomial[Floor[(n+k)/2], Floor[k/2]]; Table[T[n,k],{n,0,11},{k,0,n}] (* _Stefano Spezia_, Aug 23 2022 *)
%o A096921 (PARI) T(n, k) = binomial((n+k)\2, k\2); \\ _Michel Marcus_, Oct 29 2022
%Y A096921 Cf. A026010 (row sums), A016116 (diagonal sums), A001405 (main diagonal).
%K A096921 easy,nonn,tabl
%O A096921 0,6
%A A096921 _Paul Barry_, Jul 15 2004