OFFSET
0,2
COMMENTS
For comments see A326480.
FORMULA
From Emanuele Munarini, Aug 22 2022: (Start)
E.g.f. for the sequence of the absolute values: (1+tan(2*t))/cos(2*t).
|a(2*n)| = 2^(2*n) |E(2*n)|.
MAPLE
# The function E2(n) is defined in A326480.
seq(subs(x=1/2, 2^n*E2(n)), n=0..22);
CROSSREFS
KEYWORD
sign
AUTHOR
Peter Luschny, Jul 12 2019
STATUS
approved