Number of nontrivial compositions of differential operations and directional derivative of the n-th order on the space R^9.
A187107
Number of nontrivial compositions of differential operations and directional derivative of the n-th order on the space R^9.
Terms
- a(0) =8a(1) =8a(2) =9a(3) =10a(4) =12a(5) =15a(6) =20a(7) =28a(8) =41a(9) =62a(10) =96a(11) =151a(12) =240a(13) =384a(14) =617a(15) =994a(16) =1604a(17) =2591a(18) =4188a(19) =6772a(20) =10953a(21) =17718a(22) =28664a(23) =46375a(24) =75032a(25) =121400a(26) =196425a(27) =317818a(28) =514236a(29) =832047
External references
- oeis: A187107