E.g.f. S(x,y) = sin(x) / sqrt(1 - sin(x)^2 - sin(y)^2).

Terms

a(0) =1a(1) =2a(2) =1a(3) =16a(4) =8a(5) =5a(6) =272a(7) =136a(8) =94a(9) =61a(10) =7936a(11) =3968a(12) =2840a(13) =2108a(14) =1385a(15) =353792a(16) =176896a(17) =128704a(18) =100096a(19) =76474a(20) =50521a(21) =22368256a(22) =11184128a(23) =8211200a(24) =6531968a(25) =5261120a(26) =4079408a(27) =2702765a(28) =1903757312a(29) =951878656