Let H_n = n-th Hilbert matrix; sequence gives 1 / ( det(H_n) * denominator(permanent(H_n)) ).

Terms

a(0) =1a(1) =1a(2) =1a(3) =27a(4) =567a(5) =1a(6) =1a(7) =1a(8) =7a(9) =9a(10) =5103a(11) =1275989841a(12) =992436543a(13) =48629390607a(14) =169706648853a(15) =40257567a(16) =63a(17) =1a(18) =7a(19) =31a(20) =1a(21) =3969a(22) =25865973a(23) =117649a(24) =117649a(25) =16807a(26) =49a(27) =9a(28) =81a(29) =117369