A226297 Number of primitive permutations with n buds and 4 red or blue elements.
1, 12, 159, 2388, 40221, 751032
Offset: 0
Links
- Adrian Ocneanu, On the inner structure of a permutation: bicolored partitions and Eulerians, trees and primitives, arXiv preprint arXiv:1304.1263 [math.CO], 2013.