Number of meaningful differential operations of the n-th order on the space R^7.

Terms

a(0) =7a(1) =13a(2) =24a(3) =45a(4) =84a(5) =158a(6) =296a(7) =557a(8) =1045a(9) =1966a(10) =3691a(11) =6942a(12) =13038a(13) =24516a(14) =46055a(15) =86585a(16) =162680a(17) =305809a(18) =574624a(19) =1080106a(20) =2029680a(21) =3814941a(22) =7169145a(23) =13474502a(24) =25322375a(25) =47592650a(26) =89441626a(27) =168100324a(28) =315917527a(29) =593742597