OFFSET
0,1
MAPLE
seq(coeff(series(tan(sec(x)-sech(x)), x, 100), x, 2+4*n)*(2+4*n)!, n=0..23); # Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 13 2010
MATHEMATICA
With[{nn=50}, Take[CoefficientList[Series[Tan[Sec[x]-Sech[x]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 4}]] (* Harvey P. Dale, Mar 07 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 13 2010
Further terms from N. J. A. Sloane, Dec 17 2011
STATUS
approved