cp's OEIS Frontend

A341739 Square array T(n,k), n >= 1, k >= 1, read by antidiagonals, where T(n,k) = Product_{a=1..n-1} Product_{b=1..k} (4*sin(a*Pi/n)^2 + 4*sin((2*b-1)*Pi/(2*k))^2).

%I A341739 #17 Feb 19 2021 18:30:12
%S A341739 1,1,8,1,36,49,1,200,625,288,1,1156,12544,9216,1681,1,6728,279841,
%T A341739 583200,130321,9800,1,39204,6385729,44408896,24611521,1822500,57121,1,
%U A341739 228488,146410000,3546167328,6059221281,1003520000,25411681,332928
%N A341739 Square array T(n,k), n >= 1, k >= 1, read by antidiagonals, where T(n,k) = Product_{a=1..n-1} Product_{b=1..k} (4*sin(a*Pi/n)^2 + 4*sin((2*b-1)*Pi/(2*k))^2).
%e A341739 Square array begins:
%e A341739      1,      1,        1,          1,             1, ...
%e A341739      8,     36,      200,       1156,          6728, ...
%e A341739     49,    625,    12544,     279841,       6385729, ...
%e A341739    288,   9216,   583200,   44408896,    3546167328, ...
%e A341739   1681, 130321, 24611521, 6059221281, 1612940640256, ...
%o A341739 (PARI) default(realprecision, 120);
%o A341739 T(n, k) = round(prod(a=1, n-1, prod(b=1, k, 4*sin(a*Pi/n)^2+4*sin((2*b-1)*Pi/(2*k))^2)));
%Y A341739 Main diagonal gives A341478(n)^2.
%Y A341739 Cf. A341533, A341738, A341741.
%K A341739 nonn,tabl
%O A341739 1,3
%A A341739 _Seiichi Manyama_, Feb 18 2021