Expansion of tan(x)/cosh(x).A003702Expansion of tan(x)/cosh(x).Terms a(0) =1a(1) =-1a(2) =21a(3) =-141a(4) =10441a(5) =-183481a(6) =29429661a(7) =-987318021a(8) =276117553681External referencesoeis: A003702