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A340475 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Product_{a=1..n} Product_{b=1..k} (4*sin(a*Pi/(2*n+1))^2 + 4*sin(b*Pi/(2*k+1))^2). 3
1, 1, 1, 1, 6, 1, 1, 29, 29, 1, 1, 139, 500, 139, 1, 1, 666, 8329, 8329, 666, 1, 1, 3191, 138301, 463736, 138301, 3191, 1, 1, 15289, 2295701, 25543057, 25543057, 2295701, 15289, 1, 1, 73254, 38105729, 1404312491, 4614756624, 1404312491, 38105729, 73254, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,5
LINKS
FORMULA
T(n,k) = T(k,n).
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, ...
1, 6, 29, 139, 666, ...
1, 29, 500, 8329, 138301, ...
1, 139, 8329, 463736, 25543057, ...
1, 666, 138301, 25543057, 4614756624, ...
PROG
(PARI) default(realprecision, 120);
{T(n, k) = round(prod(a=1, n, prod(b=1, k, 4*sin(a*Pi/(2*n+1))^2+4*sin(b*Pi/(2*k+1))^2)))}
CROSSREFS
Rows and columns 0..1 give A000012, A030221.
Main diagonal gives A127605.
Sequence in context: A105373 A296548 A201461 * A368848 A265603 A174186
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Jan 09 2021
STATUS
approved

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Last modified June 13 05:35 EDT 2024. Contains 373366 sequences. (Running on oeis4.)