Matrix cube of triangle A121412.

Terms

a(0) =1a(1) =3a(2) =1a(3) =12a(4) =3a(5) =1a(6) =76a(7) =15a(8) =3a(9) =1a(10) =711a(11) =118a(12) =18a(13) =3a(14) =1a(15) =9054a(16) =1317a(17) =169a(18) =21a(19) =3a(20) =1a(21) =147471a(22) =19311a(23) =2190a(24) =229a(25) =24a(26) =3a(27) =1a(28) =2938176a(29) =352636