Sequence generated from the E6 Cartan matrix.

Terms

a(0) =1a(1) =2a(2) =5a(3) =14a(4) =42a(5) =132a(6) =430a(7) =1444a(8) =4981a(9) =17594a(10) =63441a(11) =232806a(12) =866870a(13) =3266460a(14) =12426210a(15) =47629020a(16) =183638729a(17) =711285170a(18) =2764753405a(19) =10775740030a(20) =42086252770a(21) =164635420788a(22) =644811687734