A359554 Denominator of the coefficient of x^(2n+1) in the Taylor series expansion of sin(sin(x)).

1, 3, 10, 315, 2520, 49896, 97297200, 638512875, 126309456000, 47517617347200, 2934911659680000, 105192125402364000, 1178623253808000000, 1329207696584271504000000, 77094046401887747232000000, 10455880043256025718340000000, 6973521679375808310673920000000

Offset: 0

Author

Kevin Ryde, Jan 11 2023

Keywords

• sign
• frac
• easy

Comments

Numerators are A359553, see there for details.

Links

• Kevin Ryde, Table of n, a(n) for n = 0..220
• Christopher Towse, Iteration of Sine and Related Power Series, Mathematics Magazine, volume 87, number 5, December 2014, pages 338-349.

Crossrefs

Cf. A359553 (numerators), A003712 (e.g.f. sin(sin(x))).

Programs

PARI

a_vector(len) = apply(denominator, Vec(substpol(sin(sin(Ser('x,,2*len)))/'x, 'x^2,'x)));

Formula

a(n) = denominator of A003712(n)/(2n+1)!.