OFFSET
0,2
FORMULA
a(n) = b(n+1) where b(n) = K(n,1)*I(0,1) - (-1)^n*I(n,1)*K(0,1), K(n,x) and I(n,x) Bessel functions. - Peter Luschny, Sep 14 2014
a(n) = Sum_{0..n} |A369585(n)|. - Peter Luschny, Jan 30 2024
a(n) = 2*n*a(n-1) + a(n-2). - Christian Krause, Aug 18 2024
MAPLE
b := n -> BesselK(n, 1)*BesselI(0, 1)-(-1)^n*BesselI(n, 1)* BesselK(0, 1);
A036243 := n -> b(n+1):
seq(simplify(A036243(n)), n=0..18); # Peter Luschny, Sep 14 2014
MATHEMATICA
Table[Denominator[FromContinuedFraction[Range[0, 2n, 2]]], {n, 0, 20}] (* Harvey P. Dale, Feb 18 2016 *)
PROG
(PARI) a(n)=contfracpnqn(vector(n+1, i, 2*i-2))[2, 1];
vector(22, n, a(n-1)) \\ M. F. Hasler, Feb 08 2011; edited by Michel Marcus, Feb 12 2024
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
EXTENSIONS
a(0) = 1 prepended by Peter Luschny, Jan 30 2024
STATUS
approved