OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..62
FORMULA
If n is odd, a(n) = A341535(n)/2.
If n is odd, a(n) = A341478(n).
a(n) ~ exp(2*G*n^2/Pi) / (2^(3/4) * (1 + (1 + (-1)^n)/sqrt(2))), where G is Catalan's constant A006752. - Vaclav Kotesovec, Mar 18 2023
MATHEMATICA
Table[Sqrt[Product[Product[(4*Sin[(2*j - 1)*Pi/(2*n)]^2 + 4*Sin[2*k*Pi/n]^2), {j, 1, n}], {k, 1, n - 1}]], {n, 0, 15}] // Round (* Vaclav Kotesovec, Mar 18 2023 *)
PROG
(PARI) default(realprecision, 120);
a(n) = round(sqrt(prod(j=1, n, prod(k=1, n-1, 4*sin((2*j-1)*Pi/(2*n))^2+4*sin(2*k*Pi/n)^2))));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 19 2021
STATUS
approved