Engel expansion of tanh(1).

Terms

a(0) =2a(1) =2a(2) =22a(3) =50a(4) =70a(5) =29091a(6) =49606a(7) =174594a(8) =260086a(9) =1395138a(10) =8755202a(11) =13452935a(12) =34664211a(13) =89502392a(14) =490611832a(15) =1152519711a(16) =2034899286a(17) =2281723269a(18) =3511022987a(19) =12377674446a(20) =17495576384a(21) =21346545848a(22) =115293211710