A triangle of numbers related to triangle A030526.

Terms

a(0) =1a(1) =5a(2) =1a(3) =30a(4) =15a(5) =1a(6) =210a(7) =195a(8) =30a(9) =1a(10) =1680a(11) =2550a(12) =675a(13) =50a(14) =1a(15) =15120a(16) =34830a(17) =14025a(18) =1725a(19) =75a(20) =1a(21) =151200a(22) =502740a(23) =287280a(24) =51975a(25) =3675a(26) =105a(27) =1a(28) =1663200a(29) =7692300