Third diagonal sequence of triangle A115127.

Terms

a(0) =10a(1) =30a(2) =95a(3) =311a(4) =1043a(5) =3564a(6) =12363a(7) =43420a(8) =154088a(9) =551684a(10) =1990326a(11) =7228417a(12) =26405725a(13) =96961560a(14) =357688755a(15) =1324982160a(16) =4926502020a(17) =18379785300a(18) =68783559810a(19) =258141170430a(20) =971310800694