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A340432
Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = 4^(2*n*k) * Product_{a=1..n} Product_{b=1..k} (1 - sin(a*Pi/(2*n+1))^2 * cos(b*Pi/(2*k+1))^2).
3
1, 1, 1, 1, 13, 1, 1, 121, 181, 1, 1, 1093, 18281, 2521, 1, 1, 9841, 1690781, 2803921, 35113, 1, 1, 88573, 152963281, 2732887529, 430503601, 489061, 1, 1, 797161, 13755675781, 2555011015201, 4447515497881, 66102491401, 6811741, 1
OFFSET
0,5
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, ...
1, 13, 121, 1093, 9841, ...
1, 181, 18281, 1690781, 152963281, ...
1, 2521, 2803921, 2732887529, 2555011015201, ...
1, 35113, 430503601, 4447515497881, 43384923739812577, ...
PROG
(PARI) default(realprecision, 120);
{T(n, k) = round(4^(2*n*k)*prod(a=1, n, prod(b=1, k, 1-(sin(a*Pi/(2*n+1))*cos(b*Pi/(2*k+1)))^2)))}
CROSSREFS
Main diagonal gives A340295.
Sequence in context: A342891 A174694 A353952 * A156539 A172300 A022176
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Jan 07 2021
STATUS
approved