Matrix cube of triangle A104980.

Terms

a(0) =1a(1) =3a(2) =1a(3) =15a(4) =6a(5) =1a(6) =93a(7) =39a(8) =9a(9) =1a(10) =675a(11) =285a(12) =75a(13) =12a(14) =1a(15) =5577a(16) =2331a(17) =657a(18) =123a(19) =15a(20) =1a(21) =51555a(22) =21153a(23) =6207a(24) =1269a(25) =183a(26) =18a(27) =1a(28) =526809a(29) =211227