

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
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OFFSET

0,4


LINKS

Table of n, a(n) for n=0..29.


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
Adjacent sequences: A009386 A009387 A009388 * A009390 A009391 A009392


KEYWORD

sign,easy


AUTHOR

R. H. Hardin


EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997


STATUS

approved



