2nd diagonal of triangle in A255494.

Terms

a(0) =1a(1) =13a(2) =130a(3) =1106a(4) =8575a(5) =62475a(6) =435576a(7) =2939208a(8) =19342285a(9) =124800361a(10) =792586270a(11) =4969028750a(12) =30822650251a(13) =189500937303