Subdiagonal of square array A081297.

Terms

a(0) =1a(1) =1a(2) =13a(3) =41a(4) =991a(5) =5461a(6) =194713a(7) =1545265a(8) =73022131a(9) =758924981a(10) =44709567013a(11) =575279386969