Diagonal sums of number triangle A092392.

Terms

a(0) =1a(1) =2a(2) =7a(3) =23a(4) =81a(5) =291a(6) =1066a(7) =3955a(8) =14818a(9) =55937a(10) =212428a(11) =810664a(12) =3106167a(13) =11942261a(14) =46047897a(15) =178000950a(16) =689580319a(17) =2676598447a(18) =10406929687a(19) =40525045518a(20) =158022343991a(21) =616950024334