Expansion of e.g.f.: exp(tanh(x))/cos(x).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =12a(6) =128a(7) =464a(8) =1296a(9) =336a(10) =85600a(11) =838752a(12) =4372160a(13) =-11036608a(14) =148860416a(15) =5128035072a(16) =54261590272a(17) =-109537337088