OFFSET
0,6
COMMENTS
Inverse binomial transform of A062272.
FORMULA
E.g.f.: (1+exp(-2x))(sec(x)+tan(x))/2.
a(n) ~ n! * (1+exp(-Pi)) * (2/Pi)^(n+1). - Vaclav Kotesovec, Sep 29 2013
MATHEMATICA
CoefficientList[Series[(1+1/E^(2*x))*(1+Sin[x])/Cos[x]/2, {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Sep 29 2013 *)
PROG
(Python)
from itertools import islice, accumulate
def A097953_gen(): # generator of terms
blist, m = tuple(), 1
while True:
yield (blist := tuple(accumulate(reversed(blist), initial=(m+1)//2)))[-1]
m *= -2
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul Barry, Jan 21 2005
STATUS
approved