Main diagonal of array A083861.

Terms

a(0) =0a(1) =1a(2) =5a(3) =22a(4) =105a(5) =551a(6) =3125a(7) =18901a(8) =120785a(9) =809956a(10) =5669525a(11) =41253125a(12) =310968905a(13) =2421594449a(14) =19434554165a(15) =160416509794