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A009606
Expansion of e.g.f. sinh(tan(x))*sin(x) (even powers only).
2
0, 2, 8, 168, 5760, 310304, 23894144, 2481859968, 333725331456, 56329065984512, 11650274400684032, 2895770490247219200, 851263005980215443456, 292012329049579197046784, 115560631410392130840461312, 52240866338892496235877335040
OFFSET
0,2
LINKS
FORMULA
a(n) = 2*A024259(n).
MAPLE
seq(factorial(k) * coeftayl(sinh(tan(x))*sin(x), x = 0, k), k=0..30, 2); # Muniru A Asiru, Feb 01 2018
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[Sinh[Tan[x]]Sin[x], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Dec 27 2011 *)
PROG
(PARI) my(x='x+O('x^40)); v=Vec(serlaplace(sinh(tan(x))*sin(x))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Jan 30 2018
CROSSREFS
Cf. A024259.
Sequence in context: A012540 A346164 A175538 * A009682 A076548 A167009
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested by Olivier Gérard, Mar 15 1997
More terms from Harvey P. Dale, Dec 27 2011
STATUS
approved