0,3

Unsigned sequence satisfies a(n)=na(n-1)+b(n-1) where b(n) is defined in A009006. E.g.f. tanh(z)/(1-z) - Mario Catalani (mario.catalani(AT)unito.it), Feb 10 2003

Tanh[ x ]/(1+x)

Adjacent sequences: A009835 A009836 A009837 this_sequence A009839 A009840 A009841

Sequence in context: A026089 A052835 A009565 this_sequence A088335 A066318 A066952

sign,easy

R. H. Hardin (rhhardin(AT)att.net)

Extended with signs Mar 15 1997 by Olivier Gerard.