Expansion of tanh(x)*tan(tan(x))/2.A024266Expansion of tanh(x)*tan(tan(x))/2.Terms a(0) =0a(1) =1a(2) =4a(3) =184a(4) =8256a(5) =791552a(6) =99776000a(7) =18222789632External referencesoeis: A024266