Expansion of sin x + cos x + tan x + sec x.

Terms

a(0) =2a(1) =2a(2) =0a(3) =1a(4) =6a(5) =17a(6) =60a(7) =271a(8) =1386a(9) =7937a(10) =50520a(11) =353791a(12) =2702766a(13) =22368257a(14) =199360980a(15) =1903757311a(16) =19391512146a(17) =209865342977