Engel expansion of tan(1/2).

Terms

a(0) =2a(1) =11a(2) =54a(3) =136a(4) =1473a(5) =3483a(6) =36244a(7) =41086a(8) =305728a(9) =379955a(10) =582669a(11) =4540387a(12) =5020443a(13) =22096761a(14) =24228660a(15) =48364856a(16) =178868536a(17) =234516235a(18) =524137295a(19) =1096104266a(20) =11627672572a(21) =19828856452a(22) =31372689367a(23) =47247829739a(24) =701124643395