1-pennant {(1)} - #1
2-pennant {(1,1),(2)} - #2
3-pennant {(1,1,1),(1,2),(2,1)} - #3
4-pennant {(1,1,1,1),(2,2),(1,1,2),(1,2,1),(2,1,1)} - #5
5-pennant {(1,1,1,1,1),(2,1,1,1),(1,2,1,1),(1,1,2,1),
(1,1,1,2),(2,2,1),(2,1,2),(1,2,2)} - #8
If one observe carefully they are the terms(part of) a Fibonacci series. (0,1,1,2,3,5,8,13 ....). Hence the # of 10-pennant is the 12th term of the series ie. 89