A367519 Denominators of even-numbered Maclaurin coefficients of sqrt(tan(x)/x).

1, 6, 360, 3024, 1814400, 887040, 72648576000, 784604620800, 13857951744000, 196503623737344000, 8430005458332057600000, 1249560422395084800000, 747275354440475148288000000, 25197383852207757066240000, 2105181427080881417748480000000, 154617478967448121358942208000000

Offset

0,2

Comments

Denominators of Maclaurin coefficients of sqrt(tan(sqrt(x))/x^(1/4).

Links

Robert Israel, Table of n, a(n) for n = 0..224

Formula

sqrt(tan(x)/x) = Sum_{k=0..oo} A367518(k)/a(k) * x^(2*k).

Example

sqrt(tan(x)/x) = 1 + (1/6) * x^2 + (19/360) * x^4 + (55/3024) * x^6 + ...

Maple

S:= series(sqrt(tan(x)/x), x, 41):
seq(denom(coeff(S, x, i)), i=0..40, 2);

Crossrefs

Cf. A036279, A367518.

Sequence in context: A197611 A233463 A290782 * A002684 A036281 A202367

Adjacent sequences: A367516 A367517 A367518 * A367520 A367521 A367522

Keyword

nonn,frac

Author

Robert Israel, Nov 21 2023

Status

approved