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A009158
Expansion of cosh(tan(tan(x))).
0
1, 1, 17, 673, 48033, 5387009, 871869745, 192177458593, 55316788832065, 20139680768683777, 9044546204411462737, 4909707244721993221025, 3168104630099094560839393, 2396238201505538217521920001
OFFSET
0,3
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Cosh[Tan[Tan[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 18 2024 *)
CROSSREFS
Sequence in context: A063941 A089018 A118769 * A012050 A012157 A012137
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested Mar 15 1997 by Olivier Gérard.
Previous Mathematica program replaced by Harvey P. Dale, Aug 18 2024
STATUS
approved