Number of meaningful differential operations of the n-th order on the space R^9.

Terms

a(0) =9a(1) =17a(2) =32a(3) =61a(4) =116a(5) =222a(6) =424a(7) =813a(8) =1556a(9) =2986a(10) =5721a(11) =10982a(12) =21053a(13) =40416a(14) =77505a(15) =148785a(16) =285380a(17) =547810a(18) =1050876a(19) =2017126a(20) =3869845a(21) =7427671a(22) =14250855a(23) =27351502a(24) =52479500a(25) =100719775a(26) =193258375a(27) =370895324a(28) =711682501a(29) =1365808847