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A009389
Expansion of log(1+tanh(x))*cosh(x).
1
0, 1, -1, 3, -4, 5, -1, 7, -64, 9, 1319, 11, -49204, 13, 2653559, 15, -196707424, 17, 19194804719, 19, -2385684870724, 21, 367985503366799, 23, -68980888889771104, 25, 15445553274667315799, 27, -4071626956018456576564, 29
OFFSET
0,4
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Log[1+Tanh[x]]*Cosh[x], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Mar 09 2012 *)
CROSSREFS
From Johannes W. Meijer, May 24 2009: (Start)
The a(2*n) sequence equals the second left hand column of A160485 divided by two.
(End)
Sequence in context: A345708 A144786 A247369 * A091828 A305972 A121845
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved