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 A059446 #10 Aug 19 2024 14:59:59
%S A059446 1,1,1,2,3,2,6,10,10,6,24,42,52,42,24,120,216,300,300,216,120,720,
%T A059446 1320,1968,2268,1968,1320,720,5040,9360,14640,18576,18576,14640,9360,
%U A059446 5040,40320,75600,122400,166320,184896,166320,122400,75600,40320
%N A059446 Triangle T(n,k) = coefficient of x^n*y^k/(n!*k!) in 1/(1-x-y-x*y), read by rows in order 00, 10, 01, 20, 11, 02, ...
%F A059446 E.g.f.: 1/(1-x-y-x*y).
%F A059446 T(n, k) = n!*2^k*Hypergeometric2F1([-k, -k], [-n], 1/2). - _Detlef Meya_, Aug 18 2024
%e A059446 Triangle begins:
%e A059446 1;
%e A059446 1,1;
%e A059446 2,3,2;
%e A059446 6,10,10,6;
%e A059446 ...
%p A059446 read transforms; SERIES2(1/(1-x-y-x*y),x,y,12): SERIES2TOLISTMULT(%,x,y,12);
%t A059446 T[n_, k_] := n!*2^k*Hypergeometric2F1[-k, -k, -n, 1/2]; Table[T[n,k], {n, 0, 8}, {k, 0, n}]//Flatten (* _Detlef Meya_, Aug 18 2024 *)
%Y A059446 Cf. A008288.
%K A059446 nonn,tabl,easy
%O A059446 0,4
%A A059446 _N. J. A. Sloane_, Feb 02 2001