Generalized Narayana triangle for secant.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =6a(8) =6a(9) =1a(10) =1a(11) =10a(12) =23a(13) =10a(14) =1a(15) =1a(16) =15a(17) =65a(18) =65a(19) =15a(20) =1a(21) =1a(22) =21a(23) =150a(24) =321a(25) =150a(26) =21a(27) =1a(28) =1a(29) =28