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 A335618 E.g.f.: Sum_{n>=0} Product_{k=1..n} tan(2*k*x). 1

%I #11 Oct 02 2020 15:59:10

%S 1,2,16,304,10496,568832,44486656,4742354944,660908343296,

%T 116642430451712,25425572550148096,6708171660023824384,

%U 2106760489114215120896,776654121137653931835392,332101031506139993274843136,163037618505293422657351450624,91075662529714266445615040823296

%N E.g.f.: Sum_{n>=0} Product_{k=1..n} tan(2*k*x).

%F a(n) ~ 2^(n - 1/2) * n!^2 / G^(n+1), where G is the Catalan constant A006752.

%F a(n) = 2^n * A177382(n).

%t nmax = 20; CoefficientList[Series[Sum[Product[Tan[2*k*x], {k, 1, n}], {n, 0, nmax}], {x, 0, nmax}], x] * Range[0, nmax]!

%Y Cf. A006752, A177382.

%K nonn

%O 0,2

%A _Vaclav Kotesovec_, Oct 02 2020

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Last modified February 26 20:11 EST 2024. Contains 370352 sequences. (Running on oeis4.)