%I A009131
%S A009131 1,0,0,3,11,30,194,1785,13957,113148,1143284,13131855,156950639,
%T A009131 2005222362,28119703702,424785970245,6792043718345,115135087505400,
%U A009131 2072993596779944,39432571052652315,788564865102950035
%V A009131 1,0,0,-3,11,-30,194,-1785,13957,-113148,1143284,-13131855,156950639,
%W A009131 -2005222362,28119703702,-424785970245,6792043718345,-115135087505400,
%X A009131 2072993596779944,-39432571052652315,788564865102950035
%N A009131 Expansion of cosh(ln(1+x))/cosh(x).
%t A009131 Cosh[ Log[ 1+x ] ]/Cosh[ x ]
%Y A009131 Sequence in context: A098150 A167375 A085376 this_sequence A003554 A003523 
               A018781
%Y A009131 Adjacent sequences: A009128 A009129 A009130 this_sequence A009132 A009133 
               A009134
%K A009131 sign,easy
%O A009131 0,4
%A A009131 R. H. Hardin (rhhardin(AT)att.net)
%E A009131 Extended with signs Mar 15 1997 by Olivier Gerard.